840003 Anemometer/
Thermometer measures both
air speed and temperature
in a light weight, compact
unit. Measures air velocity
in 5 scales: m/s, km/hr, mile/
hr, knots, or ft/min, as well
as temperature in ºC or ºF.
Other features include hold,
max/min, a USB computer
interface, auto power off, low
battery indicator, and a large
LCD with dual display and
audible “beeps” when buttons
are pressed.
Measuring Air Velocity
1. P
ress the POWER button to turn the meter on.
The full display appears briefly.
2. The unit is ready for use when “vel” (velocity) and
the ambient temperature are displayed.
3. P
lace the unit in front of the air source.
The measurement is displayed.
4. P
ress the SCALE button to switch units of measure:
ft/m, mile/hr, or knots in the US mode, and m/s, km/hr,
or knots in the metric mode.
5. F
or measuring air velocity in difficult to reach areas,
press the HOLD button during the reading.
This “freezes” the measurement on the display.
Press the HOLD button again to exit this feature.
Continuous Moving Average
(displayed for up to 2 hours provided the Automatic Shut
Off feature is disabled)
1. P
ress the POWER button to turn the meter on.
2. P
lace the unit in front of the air source.
3. P
ress the MAX/MIN button. The LCD displays “AVG”
and the moving average, with updates every second.
Max/Min/Average (Single Point)
1. Press the POWER button to turn the meter on.
2. Place the unit in front of the air source.
3. Press the MAX/MIN button to record the readings.
4. Press the HOLD button before moving the meter
away from the air source.
5. Press the MAX/MIN button twice to display the
minimum velocity. “MIN” is displayed.
6. Press the MAX/MIN button again to display the
maximum velocity. “MAX” is displayed.
7. Press the MAX/MIN button again to display the
average velocity. “AVG” is displayed.
8. To clear the readings, either turn off the unit or press
the MAX/MIN button until the unit beeps twice.
Air Velocity Average (Multi-Point)
1. Press the POWER button to turn the meter on.
2. Place the unit at the first point to be measured.
3. Press the HOLD button to store the first measurement.
The unit will beep once and display “HOLD.”
4. Press the MAX/MIN button. The unit will beep once
and a digit from the one to eight will be displayed.
This represents the point being recorded. Repeat the
process up to eight times.
5. O
nce all measurements have been recorded, press
the AVERAGE button to display the average air
velocity and the number of points measured.
Default Settings (US/Metric and Baud Rate)
1.Turn on the meter by pressing both the POWER
and the AVERAGE buttons.
2. R
elease the POWER button first. Release the
AVERAGE button when “Ft/min” “M/s” “°F” and
“°C” appear on the LCD.
3. E
ither “Ft/m” and “°F” or “M/s” and “°C” will be
displayed. To switch modes, press the HOLD button
for metric, or the AVERAGE button for US settings.
4. S
ave the setting by pressing the MAX/MIN button.
“S” will display.
5. P
ress the HOLD button to continue to the baud
rate selection.
6. S
et the baud rate required by your software’s
instructions. For 840052, make sure that the software
and the meter are both set to 2400 baud rate.
7. P
ress the AVERAGE button to select 2400, or the
HOLD button for 1200.
8. To save the settings, press the MAX/MIN button.
When “S” is displayed, press the HOLD button to exit
this function.
Plug the 3.5mm cable jack into the meter’s USB output
and the 9-pin connector into the computer’s COM port.
Press the POWER button to turn the meter on.
Format: 1 Stop Bit, 8 Data bits, TXXXX.XF, VXXXXFTM,
After about 15 minutes without activity, the meter will
beep 3 times then shut off to preserve battery life.
To disable:
1. With the unit turned off, simultaneously press
the POWER and HOLD buttons.
2. Release the POWER button.
3. When “n” displays, release the HOLD button.
The meter will remain on until the POWER button
is pressed again.
Replace the 9V battery when “LOW BATTERY” is
displayed. In-spec measurements may be made for
several hours after the low battery indicator appears.
• DO NOT use the meter in air velocities that exceed
the specified range.
• DO NOT use the meter at or near hurricane wind
• DO NOT use the meter in air that exceed the
operating temperature range.
80 to 5900 ft/min
0.4 to 30 m/sec
0.9 to 68 mil/hr
0.8 to 58 knots
1.4 to 108 km/hr
-10 to 50°C
+14 to 122°F
Battery Life: Apx 100 hrs
Max. Reading: 9999
Sampling Time:
Meter = 1 second; USB output = every 2 sec.
Dimensions: 7¼" × 3" × 1¾" (184 × 76 × 44 mm)
Weight: 7 oz (198 g)
Sper Scientific warrants this product against defects
in materials and workmanship for period of five (5)
years from the date of purchase and agrees to repair
or replace any defective unit without charge. If your
model has since been discontinued, an equivalent
Sper Scientific product will be substituted, if available.
This warranty does not cover probes, batteries, battery
leakage, or damage resulting from accident, tampering,
misuse, or abuse of the product. Opening the meter to
expose its electronics will void the warranty.
To obtain warranty service, ship the unit postage
prepaid to:
8281 E. Evans Rd, Suite #103
Scottsdale, AZ 85260
The defective unit must be accompanied by a
description of the problem and your return address.
Register your product online at
within 10 days.
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