Instruction Manual

T
he Model AQH-20 Indoor Air Quality Meter reduces the number of instruments
a contractor has to carry by measuring the carbon dioxide concentration, air
temperature, and humidity in one device. A large backlit LCD display shows all
three parameters simultaneously. The Model AQH-20 can display dew point, or wet
bulb temperatures in place of the ambient temperature. Minimum, maximum, and
average readings are easily accessible through the function buttons. By pressing
the hold key, the current values are held so that they can be recorded. An audible
alarm warns the user that the current ambient conditions are becoming hazardous.
The Model AQH-20 includes a hard carrying case and four AA alkaline batteries.
OPERATING INSTRUCTIONS
Taking Measurements
Press the button to turn the meter on. The meter takes 30 seconds to warm up
before displaying the current reading.
CO
2
measurement is shown in top display
Air temperature, dew point, or wet bulb temperature is shown in lower left display
Humidity measurement is shown in lower right display
Press the button for at least one second, to activate backlight. Do the same
to turn off the backlight.
Model AQH-20 Handheld Indoor Air Quality Meter
Specifications - Installation and Operating Instructions
Bulletin ES-AQH-1
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]
S
PECIFICATIONS
Measurement Ranges:
CO
2
: 0 to 2000 ppm.
Temperature: 14 to 140°F (-10 to 60°C).
Relative Humidity: 0.0 to 99.9% RH.
Accuracy:
CO
2
: ±30 ppm ±5% of reading;
Temperature: ±0.9°F (±0.6°C);
Humidity: ±3% RH (10 to 90%), ±5% (0.0 to 9.9% or 90 to 99.9%).
Resolution:
CO
2
: 1 ppm;
Temperature: 0.1°F (0.1°C);
Humidity: 0.1% RH.
Response Time:
CO
2
: < 30 seconds;
Temperature: < 2 minutes;
Humidity: <10 minutes.
Display: Four digits for temperature/CO
2
and 3 digits for humidity.
CO
2
Sensor: Non-dispersive infrared.
Operating Temperature: 32 to 122°F (0 to 50°C).
Operating Humidity (Non-Condensing): 0 to 95% RH.
Power Requirements: (4) 1.5 V AA alkaline batteries, included, user replaceable.
Warm Up Time: 30 seconds.
Weight: 6.76 oz (200 g).
Agency Approval: CE.
Selection of Temperature Parameter
The Model AQH-20 can display ambient air temperature, dew point temperature,
or the wet bulb temperature. Press the button to cycle between air
temperature, dew point temperature, and wet bulb temperature. The temperature
and measurement type will be displayed in the lower left corner of the display.
Changing the CO
2
Alarm Set Point
Hold down for more than one second during normal mode.
When “Al” and “P1.0” are displayed on the LCD, press the button to enter
alarm setup mode.
The current alarm value will be blinking on the LCD. “Al and P1.0” will be displayed
on the bottom displays. Press the button to increase the value and press the
button to decrease the value.
81/4
[209.44]
63/4
[171.34]
RS 232
DC 9V
S
ET
HOLD
C
AL
Esc
M /AV
MODE
DP/WBT
N
X
2
11/64
[
55.07]
1
5/16
[
33.36]
MODE
DP/WBT
M /AV
N
X
DP/WBT
MODE
When Model AQH-20 experiences a large variation in
environment, the meter may take 30 seconds to respond.
NOTICE