User guide

Page | 22

MRK-D-0022 V3.1 Aeroqual Series 200, 300 & 500 User Guide

6.2. Zero Calibration

Under some circumstances the sensors may temporarily exhibit a baseline reading higher than zero

due to insufficient warm up or cross-sensitivity to other gases. In this case it is also worthwhile

checking against a standard zero air source.

1. Follow the initial set up instructions in 6.1

2. Flow zero air until the reading stabilises (about 10 minutes)

3. Initiate Zero Calibration on the Aeroqual Monitor by:

 Series 200: Press and hold the “enter” button until the word “Zeroing” appears next to

ZERO CAL. The routine will run for up to ten minutes (depending on the gas sensor

installed) and then beep to indicate completion.

 Series 300 and 500: : Enter the CALIBRATE menu by pressing the “mute” and “scroll

down” buttons for 2 seconds. From here select “ZERO CAL” then:

o Single gas heads: Toggle YES/NO using scroll button to YES then press enter.

The word “Zeroing” appears and the zero routine will run for up to ten minutes

(depending on the gas sensor installed) and then beep to indicate completion.

o Multi-gas sensor heads and T/RH probe: Press enter to bring up the OFFSET

for the Sensor head. Use the scroll buttons to change the OFFSET and enter

button to accept. Calculate the new OFFSET using the equation below:

New OFFSET = Sensor Reading/GAIN + old OFFSET

Note 1: The Series 200 can only zero calibrate single gas sensors.

Note 2: Temp/RH offsets are stored on the handheld rather than on the sensor. All other

offsets are stored on the sensors.

6.3. Span Calibration

Span calibration is only available on the Series 300 and 500. It provides an option to adjust the GAIN

of Aeroqual sensor heads. There are no optimum span concentrations for calibrating Aeroqual sensor

heads. There are however a few considerations which can guide the decision as to which span

concentration is most appropriate.