1–1. AN/GMQ–33, Transportable Cloud Height Detector
1–2. AN/TMQ–34, Meteorological Measuring Set
1–3. AN/TMQ–36, Tactical Wind Measuring Set
ou may wonder why you should know about tactical equipment. Air Force Weather (AFW) is organized along functional lines to provide weather support tailored to the mission of its various users. Since the users of AFW data have such variable requirements, and you may be called upon to use AFW tactical equipment, you should be familiar with it. For example, when hostilities erupted in Korea in the summer of 1950, Air Force personnel proved equal to the challenge. Within 48 hours after the enemy crossed the 38th parallel, AFW personnel were transmitting weather reports to our military forces from a small weather unit near Taegu. The nineties had barely begun when AFW faced a sudden and unanticipated challenge: conducting the largest overseas deployment of AFW personnel since the Southeast Asia conflict in 1968. In August 1990, AFW began its support of Operation DESERT SHIELD, the massive deployment of forces to Saudi Arabia to counter a threat from Iraq following its invasion of Kuwait. Approximately 450 weather personnel deployed in support of the effort.
Such is the track record of readiness and performance of AFW. To further prepare you to be a part of such "excellence in action" we now examine the description and operation of the AN/GMQ–33, Transportable Cloud Height Detector: the AN/TMQ–34, Meteorological Measuring Set; and the AN/TMQ–36, Tactical Wind Measuring Set.
1–1. AN/GMQ–33, Transportable Cloud Height Detector
The AN/GMQ–33 is an operator-maintained, battery-powered, stand-alone transportable cloud height detector set. It can be setup and maintained in any location in the world.
The GMQ–33 (fig. 1–1), is a self-contained, portable unit that determines and displays the base height of cloud layers directly overhead from 100 to 3,000 feet. The unit is intended to be used in the tactical environment by weather personnel in support of Air Force and Army exercise and contingency operations at landing and drop zones, bare-base airfields, and special operations fields.
The GMQ–33 is powered by either a rechargeable nickel-cadmium (NiCAD) battery or a nonrechargeable lithium battery. The system can operate continuously provided a power source is available to recharge the NiCAD battery.
The GMQ–33 weighs thirty pounds and contains:
Let’s look at the five functional modules—the optical unit, the analog card, the signal processor unit, the battery assembly, and the battery charger.
The optical unit. This unit transmits the light pulse at overhead clouds and detects the atmospheric-scattered light return. The optical unit is composed of a laser transceiver and a power supply.
Analog card. The analog card generates a timing sequence.
The signal processor. The processor performs the actual cloud height determination and initiates the test programs used to verify system performance.
Battery assembly. This assembly outputs operating power either from the NiCAD battery or from the lithium battery. Both of these batteries are capable of powering the unit for a minimum of 100 firings. The operating battery is selected by the LITHIUM BAT/NiCAD BAT switch. The NiCAD battery is used during normal operation. The lithium battery is used as a backup power source. The lithium battery also provides reliable operation in an extremely cold environment (below –31°C). The operating temperature range for the GMQ–33 is from –60°F to 131°F. The operating altitude is from –100 to 15,000 feet. It takes 1 minute for the unit to warm-up after the power is turned on.
Battery charger. The battery charger assembly provides a constant-current output to recharge the NiCAD battery.
In this lesson we cover information on some safety concerns; installing, replacing and charging the batteries; the modes of operation; setting up of the GMQ–33; turning on the GMQ–33; testing procedures; normal operations; tearing down the GMQ–33; and some preventive maintenance procedures.
Safety. Be aware of areas labeled "high voltage" before operating the equipment. The GMQ–33 is an electrical device and contains no user-serviceable parts. Do not open the case under any circumstances. When working with power sources, use extreme care. Potentially lethal voltages are present when power is applied. The optical unit is capable of generating voltages in excess of 600 volts. Removing the cover and overriding the safety interlock could expose personnel to this lethal voltage.
CAUTION: Use two persons to lift heavy objects thus avoiding possible back injury.
Although the GMQ–33 is considered to be an eye-safe laser device, do not at any time look into the lens while the equipment is in operation. When started, the optical unit emits laser radiation that may cause eye injury.
Battery. The battery compartment is located under the remote fire switch.
Installation. To install the battery:
Replacement. To replace the battery, loosen the four captive fasteners. Lift the battery assembly out of the unit and unplug the battery from the connector. Remove the rear cover from the assembly and then remove the battery. Be sure that the NiCAD battery is completely discharged.
Charging. The battery charger is mounted inside the main console and can be removed by loosening the four captive fasteners and lifting the charger outward. Loosen the two fasteners and lift the battery assembly out of its housing and unplug the battery connectors. Remove the rear cover from the assembly and then remove the battery. Attach the NiCAD battery to the charger and plug the charger into a 120/240 power source. Check to see if the green battery charger indicator light is illuminated. An illuminated green light indicates the battery charger is charging. Allow 8 to 10 hours for full recharge of the battery. Do not charge the NiCAD battery longer than 12 hours. It will begin to discharge and the length of time it holds a charge for future uses is lessened.
The NiCAD battery must be fully discharged before it can be recharged. It has a tendency to lose its recharging capability if it is recharged prior to being fully discharged. When the battery loses its recharging capability, it has established an internal lowered voltage level during successive premature chargings. Totally discharging and recharging the NiCAD several times helps to revive it. Insuring the battery is totally discharged prior to recharging extends the life of the NiCAD. To discharge the battery, turn the equipment on and operate it until the light emitting diode (LED) display is blank. Do not charge the battery until the LED display on the equipment shows the symbol "BAT", which means a low battery condition. Then recharge the battery.
Lithium batteries are nonrechargeable and explode if recharging is attempted. Old lithium batteries are considered hazardous waste and must be turned in at the base environmental shop for proper disposal.
Modes of operation. The GMQ–33 provides two modes of operation, each of which is started by a successive depression of the FIRE switch. In the initial mode, or after the first depression of the FIRE switch, a high-voltage capacitor is charged to enable laser firing. In the second mode, after the second depression of the FIRE switch, the laser is fired and a short burst of high-intensity, coherent light in the invisible region is transmitted at the clouds directly overhead. Backscatter, or reflections of the transmission by aerosols in the atmosphere, is detected by the receiver as the LIDAR (light detection and range) pulse.
An analog card converts the LIDAR pulse to a digital format for the signal processor, which develops and displays cloud height measurements up to 3,000 feet with an accuracy of ±100 feet. However, readings may be erroneous when water droplets are on the optical lens receiver or during precipitation due to the scattering of the laser beam. For each depression of the FIRE switch, the signal processor cycles the GMQ–33 through an on-line built-in test (BIT).
Setup. Before setting up the GMQ–33, look for an area that is flat and clear of any overhead obstructions. After selecting the setup site, you are now ready to setup the GMQ–33. First, press the pressure relief valve. The purpose of the valve is to equalize pressure inside with the pressure outside the compartment. This function is especially important after significant changes in elevation. Next, remove the top cover of the set. Ground the instrument by attaching a wire to the ground post on the AN/GMQ–33 and then connect the loose end to an installed grounding rod. It may be necessary to press the pressure relief valve again, since pressure may not have been sufficiently equalized. Make sure to check that the circuit breaker is off—pulled out. Remove the three leveling legs from the inside top cover of the system case and insert the legs in the three keeper plates located near the bottom of the case. Adjust the legs until the level, located on the top panel, is within the leveling circle. The leveling indicator functions like a carpenter’s bubble level. Remove the lens cap from the optical unit and verify that the receiver and transmitter lenses are clean.
Turn on procedures. First, install the dummy automated observing system (AOS) plug, if available, into the connection labeled "J1." This prevents an error code when the unit is operated. This plug may be left in place after initial use. Set the POWER/ON circuit breaker to the ON position and the OFF/DIM/BRIGHT switch to the DIM or BRIGHT position as desired. Failure to select either results in a blank display. Now, you are ready to test the GMQ–33.
Testing procedures. To begin testing, the unit must be set on its side so the optical unit is facing a solid stationary target such as a vehicle, building, or rock. The target should be at least 150 feet away and as large as possible. Adjust the height of the unit to provide a clear view of the selected target. Next, pace off the distance between the unit and the target. Now, remove the lens cap from the optical unit and the remote FIRE switch from its holder and stand to one side of the unit. Simultaneously depress and hold the FIRE switch and the TEST switch until the optical unit fires. The reading obtained must be within 50 feet of the paced off distance. Once verified, return the remote FIRE switch to its holder and place the unit in the normal operating position, with the optical unit facing up. Next, depress the TEST button and observe the following:
Normal operations. For normal operations remove the lens cap from the optical unit. Remove the remote FIRE switch, from the holder mounted on top of the set, and press the button once. Observe that the indicator flashes for 4 to 7 seconds indicating that the laser is charging, while a steady green light indicates the unit is ready to fire. During the laser charging sequence, a BIT routine is performed automatically. This BIT monitors key input/output signals and when detecting a failure, it halts the sequence and displays a failure code described in the TO.
When the indicator is steadily illuminated, stand back from the unit, and press the FIRE switch again. After a short delay, the indicator extinguishes to indicate the laser has fired. After approximately 20 seconds press the READ button, the CLD HT FEET portion of the display panel indicates the height of the cloud base. The readings are encoded as estimated heights. Take an average of three consecutive readings for more accurate results. A code of "9999" indicates there are no clouds within laser range overhead, or the unit is not leveled properly. Replace the rubber lens cap on the optical unit.
The unit may be turned off by setting the power circuit breaker to the OFF position to save battery life. Return the wired remote FIRE switch to the holder mounted on the top panel of the unit. Replace the GMQ–33 cover if precipitation is occurring or is forecast to occur. If water collects on the optical unit, use lens cleaner and a soft cloth to dry it.
Tear down process. To tear down the GMQ–33, turn off the unit by setting the power circuit breaker to the OFF position. Remove the leveling legs and return them to the holders in the top cover of the system case. Install the top cover and latch it into place.
Preventive maintenance. Use a soft lint-free cloth to keep the optical lens free of any debris. Use a vacuum cleaner, cloth, or low-pressure (<15 psi) compressed air to clean the GMQ–33 surface. If dirt is difficult to remove, apply a cloth dampened with warm water. Remove the batteries from the battery ports before shipping or storing. The GMQ–33 is not an all-weather piece of equipment. Therefore, it is not waterproof and must be taken in and out during precipitation.
After you complete these questions, you may check your answers at the end of the unit.
1. What is the GMQ–33?
2. Describe the operating range of the GMQ–33.
3. What are the five functional modules of the GMQ–33?
4. What is the operating temperature range and operating ALTITUDE range of the GMQ–33?
1. How long should the NiCAD batteries be charged?
2. How do water droplets on the optical lens receiver affect the laser beam?
3. During the test operations phase of the GMQ–33, what word is displayed if the system is operating properly?
4. In "NORMAL" operations, list the correct "SEQUENCE" of events to take a reading.
5. If "9999" is displayed on the CLD HGT FEET display and there are clouds within laser range overhead, what should you do?
1–2. AN/TMQ–34, Meteorological Measuring Set
This section contains information on the AN/TMQ–34 which is a self-contained portable meteorological measuring device. It describes the operation, setup, and tear down of the set.
The TMQ–34 (fig. 1–2) is a portable weather measuring system that, like the GMQ–33, is powered by either a rechargeable NiCAD battery or a nonrechargeable lithium battery. It, too, can operate continuously provided a power source is available to recharge the NiCAD battery, and if a spare battery is available to power the system during this period.
The TMQ–34 alphanumerically displays wind speed and direction, peak wind, temperature, dew point, barometric pressure, 3-hour pressure change, the minimum and maximum temperature, and includes equipment to manually measure rain and snow depth in a battlefield environment. The results of the measurements are displayed on the self-contained display panel, which is enabled by READ/TEST switch. Similarly, on-line built-in test (BIT) is automatic and continuous. The unit is intended to be used in the tactical environment by weather personnel in support of Air Force and Army exercise and contingency operations at landing and drop zones, bare-base airfields, and special operations fields.
The entire TMQ–34, including the system case, weighs about 20 pounds. The set contains a system case, the computer assembly with a pressure sensor, and a sensor assembly with a red sensor for temperature and a white sensor for humidity, a spare battery and battery charger assembly, screw driver, test kit, rain gauge, and snow depth gauge. The TMQ–34 can operate in temperatures ranging from a low of –51°C to 55°C or –59.5°F to 132°F. The TMQ–34 is intended for use in a tactical environment with an operating range of 100 feet below sea level to 10,000 feet above sea level. The set consists of three functional modules:
Computer assembly. This assembly consists of a computer-circuit-card assembly, a barometric-pressure transducer, and a rechargeable NiCAD battery (or the lithium battery). The NiCAD battery is used during normal operation. The lithium battery is used as a back-up power source. The lithium battery also provides reliable operation in an extremely cold environment (below –31°C).
Battery charger assembly. This provides a constant current output to recharge the NiCAD battery. The TMQ–34 is designed to operate continuously for 72 hours before a battery change or charge is required.
Sensor assembly. This assembly consists of a wind direction circuit card assembly, wind speed, temperature, relative humidity, and power supply circuit card assembly, a quadrature circuit card assembly, and the transducer assembly. The unit may be operated without the sensor assembly connected if only barometric pressure information is required.
As with any piece of equipment, there are a few general safety precautions that should be applied during all phases of operation and maintenance of the TMQ–34.
Setup. To begin the setup operation, first, press the pressure relief valve to equalize the pressure inside with the pressure outside the compartment. This function is especially important after significant changes in elevation. Next, unlatch and remove the top cover of the system case. Remove the computer assembly and set it on a flat surface or level ground. Make sure the power circuit breaker is pulled out in the OFF position. Now, remove the sensor assembly and set it on a flat surface or level ground. Connect the sensor assembly electrical connector to the connector on the side of the computer assembly. The TMQ–34 needs approximately 3 minutes to stabilize to obtain accurate readings. Replace the top cover on the system case. If snow or rainfall is to be measured, remove the snow or rain gauge from the top cover of the system case.
The setup time required should be less than 5 minutes. The time required to take an observation should also be less than 5 minutes. The TMQ–34 requires about 3 minutes for the relative humidity and the pressure sensors to stabilize. Failure to wait 3 minutes could result in inaccurate data.
Operations. To operate the TMQ–34, set the power circuit breaker to the ON position—pushed in. The power switch is normally left on to record pressure tendencies, maximum/minimum temperature, etc. Next, set the sensor function switch to position number nine. This is a built-in-test. Within 10 seconds of initial turn-on, press and release the READ/TEST switch making sure the word "WAIT" is displayed on the display panel. Wait at least 10 seconds, press and release the READ/TEST switch a second time. The system automatically performs an internal diagnostics test of the circuit boards. Make sure the entire display panel illuminates and then extinguishes. Three seconds after the READ/TEST switch is depressed, the display panel should show the word "PASS." This indicates that the system is ready for normal operation.
If "PASS" is not displayed, the failure code "FAIL," a blank panel, or an erratic display indicates a malfunction. The most common cause of a fail statement is a dead battery. If the battery is dead, replace the battery. If it still fails, rotate the sensor switch from position number one through position eight. After each position, press the READ/TEST switch, and note any failure codes that appear on the display. Refer to corrective actions for failure codes in the TO. Log out the set and provide maintenance with the error codes.
CAUTION: the sensor has a built-in automatic north-seeking compass. To minimize sensor errors, stay away from elements such as iron, steel, and magnets.
Manually check wind speed and direction, temperature, and dew point because problems with these functions may not be automatically detected by the built-in-test. The manual checks are performed to insure the TMQ–34 sensors are functioning. These checks are covered by the TO and local directives.
In normal operations, the computer assembly is suspended from the operator’s neck using the strap provided. The sensor assembly is held at arms length above the operators head, or mounted on a tripod or stand as vertical as possible. After the 3-minute stabilization period, each position is able to display accurate data except for the 3-hour pressure change. Use the following information to display the readings.
Wind direction. Set the sensor function switch to position number one. Next, press the READ/TEST switch. The 2-minute average wind direction is displayed on the panel.
Wind speed. Now, set the sensor function switch to position number two. Again, press the READ/TEST switch to obtain the 2-minute average wind speed. The reading appears on the display panel.
Temperature. For the current ambient air temperature, set the sensor function switch to position number four, and press the READ/TEST switch. The temperature readings are displayed in degrees Celsius and tenths. Round temperatures up if 0.5 or greater. There is a temperature conversion chart stenciled on the computer assembly for converting to degrees Fahrenheit.
Do not expose the sensor to direct sunlight for more than 30 minutes. This could cause a high temperature reading. To avoid this, bring the sensor into the shade or aspirate before taking reading. Allow a few minutes for the unit to settle before reading the temperature.
Dew point. To obtain the dew point, set the sensor function switch to position number five, and press the READ/TEST switch. The dew point appears on the display panel. The dew-point readings are displayed in degrees Celsius and tenths.
Peak wind direction/peak speed. Set the sensor function switch to position number three, and press the READ/TEST switch. Peak wind direction, peak speed, and time appears on the display panel. Note that the time relates to the minutes from the time of occurrence of the displayed values. These values are for the peak wind speed which has occurred since last accessing this data. Displaying data clears the memory and starts the clock for the next peak wind display. Also note that the computer assembly does not have a built-in clock.
Barometric pressure. The pressure is measured in millibars over a pressure range from 600mb to 1099mb. Pressure readings on the display drops the first digit if the pressure is <1000mb (i.e. 998.4mb reads as "98.4") and first two digits if = 1000mb (i.e. 1027.3mb reads as "27.3"). Barometric pressure readings are possible without the sensor assembly being connected. First, set the sensor function switch to position number six and depress the READ/TEST switch. The barometric pressure appears on the display panel.
If a 3-hour pressure change is required, set the sensor function switch to position number seven, again press and hold the READ/TEST switch. A 3-hour change appears on the display panel. The word "WAIT" appears on the display panel if the TMQ–34 has not been in operation for a minimum of 3-continuous hours. If there is no sign the pressure is rising, a minus sign indicates the pressure is falling.
Minimum/maximum temperature and time measurement. Next, set the sensor function switch to position number eight, and press the READ/TEST switch. The minimum temperature and time, since occurrence, then the maximum temperature and time, in minutes since occurrence, appear on the display panel. These are representative values for the time since the last reading. Subtract the minutes from the current time.
Tear down. To turn off the TMQ–34, pull the power circuit breaker out to the "OFF" position. Next, remove the battery by first loosening the four fasteners and two screws securing the cover to the computer assembly.
Disconnect the sensor assembly from the computer assembly, clean, and replace in the TMQ–34 case. Remove the NiCAD battery from the battery port and securely replace the battery port cover. Clean and replace the computer assembly and all accessories in the TMQ–34 case. Cover and latch securely.
The battery. Remember, the NiCAD battery is used during normal operation and the lithium battery is used as a back-up power source.
Installation. To install a battery in the TMQ–34, use the screwdriver provided in the system case to loosen the four captive fasteners and two screws securing the cover to the computer assembly. Next, install a lithium or NiCAD battery by inserting the connector on the battery to the connector on the computer assembly. Replace the cover to the computer assembly and tighten the fasteners and screws.
Removing and charging of the battery. Using the screwdriver, loosen the four fasteners on the battery housing and the two screws on the bottom of the battery housing. Next, remove the battery from the computer housing. For continued operation of the computer assembly without the loss of data, rapidly install the spare battery within 4 seconds. Replace the battery housing cover and tighten the four fasteners and the two bottom screws. Remove the battery charger from the system case and attach the battery to the charger.
WARNING: Make sure you are only charging a NiCAD battery. Attempting to charge any other type of battery will result in an explosion.
Connect the charger to the power source and observe that a green display light is illuminated, indicating that it is charging properly. (NOTE: Although the battery requires approximately 10 hours to be fully charged, leaving it on the charger for longer periods does not hurt the battery.)
Since NiCAD batteries are often charged when they are not fully drained, an occasional deep discharge should be performed by leaving the TMQ–34 on until the battery is completely drained and then charging it as normal. This extends the life of the battery and allows it to work longer before it drains. NiCAD batteries should be completely discharged, when possible, before recharging. Do barometer comparisons as required in AFMAN 15–111, Surface Weather Observations, Volumes 1 and 2.
After you complete these questions, you may check your answers at the end of the unit.
1. What is the AN/TMQ–34?
2. What power source is required?
3. Describe the temperature and altitude operating ranges of the TMQ–34.
4. What are the three functional modules in the TMQ–34?
5. How long can the TMQ–34 operate continuously before changing or charging the batteries?
6. What does the "Sensor Assembly" consist of?
1. When beginning the setup operation of the TMQ–34 what should be done first and why?
2. How long does it take the TMQ–34 to stabilize to get accurate readings?
3. How long should it take to setup the TMQ–34?
4. When operating the TMQ–34, what is the most common cause of a fail statement when the system encounters a fail code during the internal diagnostics test of the circuit boards?
5. When operating the TMQ–34, where is the computer assembly and the sensor assembly deployed?
6. What type of compass does the sensor assembly have?
7. How does the TMQ–34 display temperatures and dew points?
8. What is the most important thing to remember when charging the battery?
9. Why would you want to occasionally do a deep discharge on the NiCAD batteries?
1–3. AN/TMQ–36, Tactical Wind Measuring Set
This is a portable, ruggedized wind monitoring system designed for use in tactical and temporary monitoring situations. The TMQ–36 is a wind measuring set that continuously monitors and displays surface wind data. The basic system consists of a wind vane, anemometer, mast and crossarm, local display, remote display, recorder, battery, and battery charger.
The wind measuring set (fig. 1–3) is a portable wind measuring set capable of measuring wind speed, wind direction, gusts, peak wind, variability, gust spread, and standard deviation. The set displays the information and other calculated parameters at local and remote displays. The system includes a recorder unit that serves as a display unit as well as a storage device for wind data. The recorder unit has a serial interface for communication with other storage devices or computing systems. The storage media used in the recorder unit is metalized paper and the printer works on the dot matrix principle. The entire set, containing normal extend sensors, one local and three remote displays, and a recorder unit, is based on a battery power supply providing energy for 31 days. A battery charger unit and two separate sealed, maintenance-free batteries are the heart of the powering system. Included are a 10-foot portable mast for the system and carrying cases for the entire set. All units in the operational setup are waterproof and dustproof.
System cases. The TMQ–36 is contained in five cases:
These cases contain all the components and accessories, except the wire, required for 90 days of operation which is required to transfer data between the display units.
The mast case. The mast case contains the mast base plate; the lower, center, and upper sections; the mast ground stake; five ground stakes; three guying ropes; one hammer; a level; and a compass.
The sensor case. The sensor case contains the cross arm with the speed and direction sensor already installed, a speed sensor cable, a direction sensor cable, five ground stakes, five ground cables, a lightning rod, three remote displays, and the local display.
The recorder and battery charger case. The recorder and battery charger case contains the recorder and battery charger unit, AC line cable, recorder cable, two battery cables, and five rolls of paper for the recorder and TO. The recorder and battery charger units are setup in a sheltered location with operating temperatures between 0 and 49°C.
The units can be located up to 10,000 feet from the sensors without special cables. Once placed in a sheltered location, open the recorder and battery charger case. Remove the two units and place them in the desired location, preferably on a table. Next, remove the AC power cable, the two battery cables, and a roll of paper.
Battery cases. Each battery case contains a 12-volt sealed, lead acid, maintenance-free battery.
The wind speed sensor. The wind speed sensor is a high-response, low-threshold three-cup optoelectronic anemometer. The wind speed sensor has a range of 0 to 99 knots.
The wind direction sensor. This is a low-threshold optoelectronic wind vane. The sensor is based on a moving wind vane that rotates a disc attached to the sensor shaft and has a full 360° range.
The local display unit. This is a processor-based intelligent display that makes all main calculations and data manipulations in the wind measuring system. The local display can be functionally divided into the following groups of electronics and corresponding functions:
The main functions of the local display are to read sensors and make all necessary calculations. The results of these calculations may be read on demand through the local liquid crystal displays (LCDs) using front panel switches.
The data is automatically transmitted once every 5 seconds for other units through the built-in full duplex modem. The recorder unit responds normally with certain status messages using the other channel of the modem. All system alarm messages are also displayed on the local display LCDs. The local display unit may be separated up to 10,000 feet from other units using normal two-wire telephone lines. No local batteries are necessary. The telephone pair feeds both the local display unit and the sensors when connected to the battery charger unit.
Remote display units. The system may contain up to six-remote display units, but three are included in one set. The main functions of the remote displays are to receive calculated wind data on the modem line from the local display CPU. This takes place every 5 seconds. The remotes store these messages into their internal data base, from which proper messages are brought into displays on demand. All system alarm messages are automatically displayed. The last display remains on, while other alarm messages are buffered.
Remote displays may be separated up to 10,000 feet from the battery charger unit using normal two-wire telephone cable. No local batteries are required. The telephone pair feeds the remote display unit when connected to the battery charger.
Remote display units may be divided into the following main groups:
Recorder unit. The main functions of the recorder unit are to operate as a remote display unit, make a permanent record of wind data onto metalized printing paper, and provide a serial interface for other computing systems.
Every second or 12 seconds (user selectable) the recorder unit prints the time and date group, wind direction and speed, gust spread, peak wind direction and speed, time of occurrence and standard deviation in this order. The 1-hour and 24-hour peak wind and times of occurrences are printed at the next available record time, five minutes to the hour. Also, all alarm messages are recorded with the date and time.
The recorder unit may be functionally divided into the following sections:
The recorder unit is always connected directly to the battery charger unit with a special six-wire cable supplied. The length of the cable is 10 feet. Although the system may have up to six-remote display units, only one recorder unit may be connected to the wind measuring set. The recorder unit is the master timekeeper; it retains its real-time and date even when disconnected. The recorder automatically updates the software-based real time of the other displays. A user may enter a new time and date only to the recorder unit.
The AWDS interface is a serial data connection for the Automated Weather Distribution System. The baud rate is user selectable at either 300 or 1200 baud. The interface is normally inactive. It may be selected to be active by commands through the recorder front panel switches. The active or inactive state and selected baud rate are stored in the memory of the recorder unit. The 31-day operating time with batteries is available only when the AWDS interface is inactive. When it is active it draws so much current that the battery life is significantly reduced.
Battery voltage level is the most important value to be checked periodically or on request. The results are also printed on paper with time and date.
The real-time clock section runs the system real time and date. An on-board lithium battery for the real-time integrated circuit provides a nonvolatile time and date for several years. This chip contains an extra nonvolatile memory for such parameters as AWDS baud rate and on/off status’s. The clock has the only adjustment in the entire wind set. This timer should be readjusted to the exact time once a year.
The display/keyboard is exactly the same as the local and remote display circuit boards.
Battery charger unit. The battery charger serves four major functions:
At startup, the unit illuminates all three status LEDs to indicate correct operation. Then it compares the DC-level of the batteries (external) against internal reference source, and if the batteries are above minimum level, the DATA LINE and recorder are connected to these batteries. The green LED blinks to indicate this state. If the batteries become empty, all outputs are disconnected from the batteries. The red overcurrent LED is illuminated if there exists an external short. The yellow charge complete LED is lit when charge is complete. The charging time for the batteries, if fully discharged, is 48 hours.
Battery units. The system is powered by two 12-volt, 23-amp hour batteries, connected in serial with external cables. This gives a 24-volt nominal operating voltage level for the measuring set. The batteries are sealed, lead acid, and maintenance free. They may be stored in any position. Both must be connected in order for the system to use them at all. The system stays operative even if the batteries are disconnected as long as the AC source is connected. The batteries are capable of supplying power to the entire wind measuring set for up to 31 days.
Hazards. The TMQ–36 is designed to operate in wet or rainy conditions. However, to avoid injury, do not attempt to set up the system when thunderstorms are in the area. Ensure that the AC power cord is connected to the battery charger unit before plugging it into the AC outlet. Never remove the battery charger unit cover while the AC line is connected. Eye protection and gloves should be used when handling batteries, installing the grounding rod, ground stakes, and guy wires. Two people are required to lift and secure the mast. Care must be taken that your clothing and fingers do not become caught between the mating ends of the mast during assembly.
Setup. Open all the cases and inspect the system for any physical damage and missing hardware. Pay special attention to the two 12-volt batteries; no leakage nor corrosion should be present. Select a suitable place to set up the sensor mast. This should be an open area free of obstructions if possible. The TMQ–36 setup is complete when all the units have been grounded.
Recorder and power supply site installation. For proper installation, you need a ground wire and stake from the sensor case, and the hammer from the mast case. Plug the ground wire into the ground jack on the charger unit and the other end into the wire hole on the ground stake. Next, tighten the fastening screw on the ground stake. Now, hammer the ground stake into the ground the full length of the stake. Connect the batteries to the charger unit with the battery cables. The cables are labeled on each end. The charger unit is also labeled for proper connections. Locate the two batteries (two smallest square cases) and place them with the recorder and charger units. Connect the two batteries and the charger unit with the two cables. (NOTE: All cables are labeled clearly on both sides as to their respective mates.)
Turn on the "DATA LINE" switch and verify that the three LEDs all light for about 1 second. After this the green LED should blink once per second indicating a good battery. The red and yellow lights must turn off after 1 second. The green light illumination depends on the power source used. Battery power produces a green light that blinks once per second and AC power produces a green light that stays on with intermittent blinking. Connect the AC line cable and turn the "CHARGER" switch to the ON position. The charger switch is a circuit breaker that may occasionally turn off internally due to a power surge when the equipment is turned on. If the charger switch doesn’t stay on after several attempts, disconnect the AC line cable and carefully open the battery charger unit to check the voltage selector switch. Make sure the switch setting matches the AC power available. If not, position the switch appropriately. Replace and tighten the cover.
The green LED should blink regularly as before but now you should see a steady yellow light indicating a good charge on the batteries. If the yellow LED is off, then the batteries are weak. In this case, allow the batteries to charge for 48 hours. Connect the recorder unit to the charger unit with the respective cable. The recorder unit displays and prints certain start-up messages. (NOTE: Since the recorder unit can’t receive data from sensors that have not been connected, it periodically displays a "FAIL 10" message until the sensors are connected.)
The green light inside the recorder should blink once per second, and the red light should be off. Now install the recorder unit cover and tighten all four screws. Next, connect one end of the telephone wire to the positive and negative binding posts on the charger unit. Before unwinding the telephone wire to the sensors, check that the red overload light is off and the green light is on or blinking. Next, cut the wire, leaving enough slack so it may be wound around the lower section. Strip the insulation off the wire ends and insert them into the binding posts on the remote sensor. If the decimal point is not flashing after 10 seconds, switch the wires. Remove any excess wire protruding from the binding posts to avoid short circuits. Press the "D" button and verify the display on both windows for 5 seconds with the backlight illuminated. "FAIL" will appear on the upper display if the recorder unit is not installed or if it has failed. Press the "D" button to display the fail code zero one, and to acknowledge the failure. The local display is now operative.
Sensors/mast installation. The mast and sensor units are setup in a flat, outdoor location in operating temperatures of –50 to 68°C (–58 to 154° F). Make sure no obstructions exist which could cause unwarranted air turbulence around the sensors. The distance between the sensors and any obstruction should be at least 10 times the height of the obstruction. Place the base plate on the ground and align the arrow on the plate to north using the compass supplied. Place the lower mast section on the base plate and secure the base plate with two small grounding stakes and one long grounding stake. Place the remaining three grounding stakes 5 feet from the base plate at 120° apart in alignment with the three tiedowns on the base plate. Secure the sensor crossarm to the upper mast section using the threaded end of the lightning rod. Connect the grounding wire to the side of the sensor crossarm and the sensor wires to the sensors leaving the other ends unconnected. (CAUTION: the sensors must be carefully handled. Avoid all unnecessary handling of the moving parts of the sensors and never place the sensors where dust, sand, or water can enter the gaps between the sensor body and the cross or vane.) Connect the middle mast section to the top assembly and, with two people, lift the entire upper mast section to the top of the lower mast section. (NOTE: Make sure that one person remains with this assembly until the next step has been completed.)
Place three guy wires through the loops in the three grounding stakes placed earlier. Tie the ends of the three ropes to the tiedown anchors on the base plate. Loosen the guy ropes one at a time to center the mast vertically. Using the level supplied, one person holds the mast and relays to the other person those ropes which need to be tightened or loosened for proper leveling. Lower the local display unit into the slots on the center mast section. Wrap the sensor wires around the mast and connect them to their respective receptacles. Wrap the grounding wire around the mast and connect it to the long grounding stake in the base plate. Attach the field phone wire to the +/– terminals of the charger unit. Run the wire to the mast assembly and connect the wire to the local display unit terminals.
Operation. We now look at the operation of the TMQ–36. The controls and indicators of the recorder unit, the local display unit, and the remote display unit all look alike. The displays are liquid crystal offering two, four-digit windows per unit. Two yellow lights are used per window for backlight purposes. This makes the displays readable in low light conditions and in direct sunlight. The recorder unit also has a window for viewing the recorder paper. The battery charger unit has a data line, a charge on/off switch, and three status lights. The screens for the units are arranged one above the other with the four buttons labeled A, B, C, and D, directly below them. Refer to the TO to find push-button sequences and modes. There are many sequences and modes for these units.
A self test should be done for the local, remote, and the recorder unit before the use of the TMQ–36. This test is performed on all three units by depressing the "D" button, then the "A" button. This starts the unit’s self test. To stop the self test, press the "D" a second time. If no fail codes are displayed, the TMQ–36 is ready for normal use. If there is a fail code or codes, look the code(s) up in the TO. It lists a separate fail code chart for each unit. The TO lists all the fail code numbers in numerical order with an explanation of the failure and corrective actions.
To obtain the wind speed, gusts, and wind direction, depress the "A" button. This displays the data on two liquid crystal display (LCD) screens.
Turn off/Tear down. To turn off the TMQ–36, turn the battery charger unit data line switch to the "OFF" position. This stops the entire system, but the batteries are still being charged if the AC power is still connected. Turn the charger ON/OFF switch to the "OFF" position to stop the recharge. For tear down of the TMQ–36, reverse the setup procedures.
Cleaning. Clean all components before storing them in the cases. Remember to replace all the connector safety covers to keep any dirt or moisture from entering the connectors. When cleaning the components, use only water because detergents or solvents may destroy the waterproofing seals used with the system. Use the diagrams in the TO to place the components of the TMQ–36 in the correct case. The wire can be wound up and placed in one of the cases for future use.
After you complete these questions, you may check your answers at the end of the unit.
1. What function does the AN/TMQ–36 perform?
2. How long can the system operate on batteries?
3. When setting up the recorder and battery charger units in a sheltered location what is the optimum operating temperature range?
4. How far can the TMQ–36 units be located from the sensors without any special cables?
1. Describe the wind speed sensor.
2. What is the range of the wind speed sensor?
3. Describe the wind direction sensor.
4. What unit is a processor-based intelligent display that makes all calculations and data manipulations in the wind system.
5. What are the main functions of the local display unit?
6. What is the maximum number of remote display units the wind system can support?
7. What the main function of the recorder unit?
8. How many recorder units may be connected to the wind measuring set?
9. What unit serves as the master timekeeper for the TMQ–36 even when disconnected?
10. What is the baud rate for the AWDS interface?
11. How long does it take to charge the batteries when they are fully discharged?
12. How long can the batteries supply power to the wind measuring set?
13. When is the TMQ–36 setup considered to be complete?
14. Because the recorder unit of the TMQ–36 can’t receive data from sensors that are not connected, what message periodically appears until the sensors are connected?
15. What is the normal operating temperature for the mast and sensor units?
Answers to Self-Test Questions
1. The GMQ–33 is a self-contained laser cloud height set that measures and displays the base of a cloud layer directly overhead.
2. The operating range of the GMQ–33 is from 100 to 3,000 feet.
3. The optical unit, the analog card, the signal processor unit, the battery assembly, and the battery charger.
4. The operating temperature range is from –60 to 131°F. The operating altitude is from –100 to 15,000 feet.
1. NiCAD batteries should be charged for 8 to 10 hours.
2. Can cause erroneous readings.
4. Remove the lens cap from the optical unit and remove the remote FIRE switch from its holder. Press the remote FIRE switch once. When the CHARGING/RDY light shows steady green, stand clear from the unit, and press the remote FIRE switch. Wait 20 seconds, and press the READ button. The CLD HGT FEET display read the base of the cloud in feet.
5. Check to make sure the GMQ–33 is leveled properly.
1. The TMQ–34 is a self-contained tactical meteorological measuring set.
2. Rechargeable NiCAD (nickel cadmium) or nonrechargeable lithium batteries.
3. The TMQ–34 can operate in temperatures ranging from a low of –51°C to 55°C , with an operating range of 100 feet below sea level to 10,000 feet above sea level.
4. Computer assembly, battery charger assembly, and sensor assembly.
5. 72 hours.
6. A wind direction circuit card assembly, wind speed, temperature, relative humidity, and power supply circuit card assembly, a quadrature circuit card assembly, and the transducer assembly.
1. Press the pressure relief valve to equalize the pressure inside with the pressure outside the compartment. This is especially important after significant changes in elevation.
2. About 3 minutes for the relative humidity and the pressure sensors to stabilize
3. Less than 5 minutes.
4. A dead battery.
5. Drape the computer assembly over your neck and hold the sensor assembly at arms length above your head.
6. A built-in automatic north-seeking compass.
7. Degrees Celsius and tenths.
8. Make sure you are only charging a NiCAD battery, because charging any other type of battery can result in an explosion.
9. It extends the life of the battery and allows it to work longer before it drains.
1. Measures wind speed, wind direction, gusts, peak wind, variability, gust spread, and standard deviation and displays the information at local and remote locations.
2. 31 days.
3. Between 0 and 49°C.
4. Up to 10,000 feet.
1. A high-response, low-threshold three-cup optoelectronic anemometer.
2. 0 to 99 knots.
3. A low-threshold optoelectronic wind vane.
4. Local display.
5. To read the sensors and make all the necessary calculations.
7. Operates as a remote display unit, to make a permanent record of wind data and to provide a serial interface for other computing systems.
9. The recorder unit.
10. It is user selectable at either 300 or 1200 baud.
11. 48 hours.
12. 31 days.
13. When all the units have been grounded.
14. FAIL 10.
15. –50 to 69° C (–58 to 154° F).
Do the Unit Review Exercises (URE) before going to the next unit.
Unit Review Exercises
Note to Student: Consider all choices carefully, select the best answer to each question, and circle the corresponding letter. When you have completed all unit review exercises, transfer your answers to ECI Form 34, Field Scoring Answer Sheet.
Do not return your answer sheet to ECI.
Please read theunit menu for Unit 2 and continue. è