Test Products International A771 - Manual (Page 3)

GENERAL
DESCRIPTION
The A771 is an advanced state-of-the-art Carbon
Monoxide monitor that may be used to measure
levels of carbon monoxide (CO) in th part per
million (ppm) range when used with a digital
multimeter (DMM).
The instrument has both audible and visual alarms
when CO has reached the preset level. This unit
may be operated as an alarm only personal
monitor.
NOTE: The product may be used with any DMM
capable of measuring 2-4 volts DC. The signal
output is 1 mV DC = 1 ppm CO.
The A771 uses and advanced electrochemical
sensor that measures Carbon Monoxide only. A
built-in filter reduces most cross-sensitivity to
other gases. This product should be used with
DMM’s with greater than or equal to 10 megohm
impedance.
OPERATION
(Investigation Use)
1. Attach the banana jack to the COM and V input jacks
of the DMM.
2. Turn on the DMM and select the 2 or 4 volt range
DC.
3. If the voltage reading is below 4 VDC with the A771
in the off position, replace the 9 volt battery in the
A771.
4. Turn on the A771. The alarm LED with flash and the
green LED should stay on.
5. In a clean environment, adjust the zero knob until
the DMM reads zero.
6. Place the A771 in the area to be tested and read the
CO in ppm on the DMM.
7. To deactivate the alarm sound, set the slide switch
to MUTE.
OPERATION
(Monitor Use)
1. Follow steps 1-5 above.
2. Unplug the A771 from the DMM.
3. Place the A771 in the belt pouch with the sensor
facing outward.
4. If an alarm occurs, use a DMM to measure the
concentration.
5. The red LED will illuminate continuously during
alarms