TMQ-34 Meteorological Measuring Set
© Brooke Clarke 2005
Other Items in Kit
The set fits into a sealed carry
that's about 12' x 13" x 9" high.
The main component is a
multi-function weather sensor that can be either hand held or
standard american camera tripod (1/4-20 thread). It connects
the digital display unit with a short cable (but maybe a longer
could be used). The sensor contains a magnetic compass so
wind direction is reported on the Display in magnetic
This way it does not matter how the sensor is pointed, just held
still. Directly under the center of the label there's
metal tab which when removed allows the sensor to be taken apart.
There's a wind direction scale on top of the wind
speed drum with angles marked every 45 degrees, but since the drum
turns in the wind it's not much use? If the wind speed drum
spun manually it keeps on spinning for a long time indicting that
bearings are very good and that the minimum wind speed that is
detectable may be low. The cable is attached to the sensor
has a Bendix H9530-12
MS27473E10B13P connector, but only 6 pins are installed. The
sensor outputs are analog signals in the 0.1 to 5 volt range.
The sensor connector is wired as follows:
B. + 10 to +15 V @ 10 ma
C. Wind Speed 0 to 100 mph (0.1 to 5 V)
D. Wind Direction 0 to 360 deg magnetic (0.1 to 5 V)
E. Temp -58 F (-50 C) to +131 F (55 C) (0.1 to 5 V)
F. Relative Humidity 0 to 100% (0.1 to 5 V)
Long Sensor Cable
When a long cable is used with JTG06RE 10-13P and JTG06RE 10-13S
connectors there will be a DC offset caused by the cable
resistance. When using an indoor voltmeter to read the
get around this an extra wire can be run from the sensor end
terminal (pin A) back to the indoor meter ground terminal.
way the DC voltage drop in the ground lead will not be part of
voltage measurement. It's too bad that the stock TMQ-34
use this method to support extension cables. It may be
to modify the TMQ-34 to support this pseudo Kelvin measurement
method. Sure would be nice to have a schematic diagram for
Marked: Computer, Assy, p/o AN/TMQ-34, Des Act: 10241, Mfr: 10241,
No. WD8500-22, Contract No. F04606-86-C-0630
The display unit has a selector switch to
determine what the alpha numeric LED display shows:
- Wind Avg Dir (deg)
- Wind Avg Sp (Knots)
- Wind Dir-Pk Sp-Time (Deg-Knots-Min)
- Temperature (deg C)
- Dew Point (Deg C)
- Baro Pressure (Millibars)
- 3 Hr Baro Press Change
- Min Temp-Time (deg C-min) &Max Temp-Time (deg C-min)
- Test -> all pixels on in sequence then PASS or FAIL.
On one side of the display box there's a
temperature conversion nomagram covering the range -50C/-60F to
+50C/+120F, it's not clear if a user attached a stnecil or if this
The display has two major parts:
This has the battery compartment
the barometric pressure sensor that has a tube going through a
desiccant to the outside atmosphere. The "Power" circuit
and the connector for the hand held sensor.
This has a circuit board attached
has all the electronics for the weather station (except for the
pres specific stuff). Uses a 12 to 5 Volt DC-DC
and a couple of crystals (1.048576 & 3.68640 MHz).
Included with the set is a Lufkin
six foot folding wood ruler. Maybe this is used
the height of the sensor above
Another possible use would be to measure the depth of snow.
There is a "GAGE, PRECIPITION
ML-614/G". (spelling should be gauge & precipitation).
to both 2
inches and 50 mm. The bottom end has a 0.22" diameter hole
0.7" deep to hold it, but what does that fit in the kit?
there is another part stowed inside the rain gage, but it's
not clear. Ans: I have parts of 2 different style gauges
"Kit, Sensor Test" that contains two parts:
One is a hollow plastic cone with a metal rod coming out the
pointed end. Use unknown
The other is a plastic clip that can be slipped onto the sensor
direction or speed rotors and when the sensor is held with it's
parallel to the ground the rotor should turn because of the weight
the clip. If the rotor does not turn there's too much
The Philips screw driver is needed to open the battery
The handle with a 1/4-20 screw on top fits the bottom of the
hand held use.
The neck strap clips onto the display so no hands are needed for
holding the display. One hand to hold the sensor and one
set the display switch and press the measure button.
Remove assembly and place on flat surface. Verify PWR circuit is
(pulled out). Remove top of assembly and insert
battery. Replace cover. Connect sensor assembly to
Operation: Set PWR
breaker to 'ON' position (pushed in). Set SENSOR FUNCTION
to position 9 (test). Within 10 seconds of initial
depress and release READ/TEST button and observe the word WAIT
seconds) on the panel. Wait at least 10 seconds, depress and
the Read/Test button and observe: 1) All pixels on the first and
segments illuminate and then disappear; then the second
fourth segments illuminate and disappear. (2) The display panel
indicates PASS three seconds after the READ/TEST is depressed.
indicates the unit is ready for normal operation. If PASS is not
displayed, a failure code will indicate a malfunction.
Wind Direction: Set
function switch to position 1. Depress and release
Wind Speed: Set function
to position 2. Depress and release READ/TEST switch.
4 (READ/TEST switch).
Average Wind Direction:
Function position 1. Wait three minutes and depress READ/TEST
Average Wind Speed: Function position 2. Wait three minutes and
Average Wind Speed:
position 2. Wait three minutes and press READ/TEST
Wind Direction/Peak Speed:
position 5. Depress READ/TEST button.
Turn-Off: Set PWR
breaker to off (pulled out). Remove battery. Disconnect
When the battery is installed the
barometric pressure sensor starts logging data so that when the 3
baro pressure change test is run there will be something to
To get the display to turn on the
Read/Test Hold button needs to be pressed and released.
The POWER button appears to be a circuit breaker
and it's normal position is down. If it pops up there may be
problem. You can manually lift the button to turn off the
22 April 2005 - my Loran-C receivers both lost lock and the
lamp on the Loran-C filter has been flashing, so I'm expecting a
thunder storm. So started logging the baro pressure.
9:35 pm PDT measured inside:
- Wind Avg Dir (deg) = 226.2
- Wind Avg Sp (Knots) = 21
- Wind Dir-Pk Sp-Time (Deg-Knots-Min) = 128.1 2.2 0.
- Temperature (deg C) = 27.4 (BATT CC#2 HH#2) The strange
caused by holding the button down.
- Dew Point (Deg C) = 18.9
- Baro Pressure (Millibars) = 981.3
- 3 Hr Baro Press Change = 1.3
- Min Temp-Time (deg C-min) & Max Temp-Time (deg C-min)=
- = FAIL if battery is low. PASS if battery is OK.
Note if the battery is changed quiclkey the 3 hour baro pressure
Test results depend on battery condition & how the button is
pressed, HH#3, HH#4, 502 with weak
battery, and 250.4, .6, 0. with good battery.
In the photo on the
left the sensor is mounted on a mast which seems to be supported
by 3 or
4 white tape ribbons and the computer is on a stack of weather
cases. The photo caption on the FAS web page is:
"Airman First Class Eric Andrews takes an observation with the
Tactical Meteorological Sensor."
How is the sensor attached to the mast, does it just plug in?
The digital barometer was made by
Atmospheric Instrumenttin Research (A.I.R.) which is now part of Vaisala
. Model number
sensor is AIR-DB-2ATS1. The code in the uP is patented by
Patents held by A.I.R.:
Class 73 Measuring & Testing
335 - Hygrometer
170 - radiosonde
Class 342 Communication: Directive Radio Wave SYSTEMS &
(e.g. RADAR, Radio Navigation
357.12 - GPS receiver signal processing
Relative humidity sensing apparatus Sep 13, 1994 73/335.04
Method and apparatus for tracking the position and
of airborne instrumentation Sep 13, 1994 342/357.12
Meteorological data encoder for measuring
conditions March 13, 1990 73/170.28
; 73/724; 374/170
The display box holds a BA-5557/U or BB-557/U NSN
The BB-557 is a Ni-Cad battery rated at 0.45 amp hours. The
battery label says to charge it at 100 ma for 6 hours.
Note the BB-557/U is a smaller version of the BA-5590
It has the same socket as a BB-390 or BB-590 and the socket is
The display has the battery plug pin 1 connected to pin 2, and it
pin 4 connected to pin 5. This puts the two "12 Volt"
in parallel. So the weather station operating voltage
be 10 to 15 VDC.
The design of the display battery compartment is such that a BA-5590
will NOT fit when the cover is removed. That's because the
is 4 3/16" long and the BA-5590 is 4 3/8" long. If they
have made the "notch" in the display box a little longer you could
a BA-5590 family battery when the cover was removed.
Battery charger plug has a jumper between pins 2 and 4 and so is
charging the two halves in series with pin 3 being the negative
and 5 being the positive terminal. This way you can not charge a
primary (BA-5557) battery. There are two spare 250 v, 1/4A
inside the box.
The power transformer can be strapped for either 110 or 220 VAC
input. Both the
input and the output are fused. There are a couple of
inserts that would allow this charger to be mounted to something,
what is not clear. Maybe the charger is also used in other
applications. The Green LED BAT CUR indicator only comes on
current is being supplied to the battery. So if a BA-5590 is
connected there is no charge current (no pin 3 connection in the
battery) and no LED light.
The circuit appears to be a transformer fed bridge rectifier
single pass transistor. 44 is the open circuit output
voltage. If the internal resistance was 425 Ohms then when a
Volt battery was connected the current would be about 40 ma.
a dead battery (20 V) the current would be about 60 ma. This
not be correct, but is close to the recomended 100 ma charge
for the BB-557/U.
The trickle charge current is about 40 ma into a string of 20
cells that are fully charged. This charger may be able to
Meteorological Measuring Set, dated 15 Apr 00. Replaces 1 Oct 99
2. The following publications have been
rescinded. Customers will dispose of stock in accordance with
AFJQS2E1X2-206TD, AN/TMQ-34 Meteorological Measuring Set dated
GMQ-33 Cloud Height Set
Cloud Sensors - based on temperature
difference looking up and down