AQ EXPERT Instruction & Operations Manual
Version 1.13
Page 29 of 63
CHAPTER 9
ZERO & SPAN CALIBRATION
Every instrument must occasionally be tested against some known value or standard in
order to make sure that its accuracy has not deteriorated. If the instrument is reading
outside of the stated accuracies in this manual, the unit should be calibrated by
following the procedures described in this chapter.
This chapter will contain all of the information on calibrating and adjusting the AQ Expert
IAQ Monitor. The term Span Calibration means comparing the AQ Expert
’s readings to
a standard concentration (i.e.: calibrated gas bottles) and adjusting/changing the AQ
Expert
’s individual sensor’s readings to match the standard concentration for the most
accurate measurements. The term
ZERO calibration refers to the user’s ability to
calibrate each sensor with zero concentration of the targeted gas. See Chapter 11,
Maintenance, for recommended frequencies of each procedure.
If the unit is returned to E Instruments for Span Calibration, the unit will be shipped back
after Calibration with a new Calibration Certificate valid for one (1) year. If the unit is
Span Calibrated in the field, the original calibration certificate is no longer valid.
The CALIBRATION MENU lets you set span calibration
values for each sensor and performs all sensor
calibrations. The CALIBRATION MENU is shown below
A brief explanation of the parameters shown follows
below:
ZERO GAS SENSORS
: This will set the zero point of
CO, NO, NO
2
, SO
2
, H
2
S, CH
2
O, O
2
, VOCs, Pressure &
Velocity values.
ZERO CO
2
SENSOR:
This will set the zero point of CO
2
.
ZERO THERMOCOUPLE
: This calibrates the external
thermocouple input (T1) to ambient temperature.
**** CALIBRATION ****
Zero Gas Sensors
Zero CO2 Sensor
Zero Thermocouples
Zero Errors
Zero Time: 60sec
Span Time: 120sec
** Span Lockout **
Sensor History
Span CO: xxxx PPM
Span H2: xxxx PPM
Span CO2: xxxx PPM
Span NO: xxxx PPM
Span NO2: xxxx PPM
Span SO2: xxxx PPM
Span H2S: xxxx PPM
Span FMH: xxxx PPB
Span Ozone:xxxx PPB
Span VOC: xxxx PPB
Span Velocity: xx "
Span
∆
P: xx "
Span AmbT: xx.x C
Span BP: xxxx mbar
Span RH: xx.x %
Cal Thermcple1:xxxF
Cal Thermcple2:xxxF
NOTE: CO
2
should ALWAYS be Span Calibrated or Zeroed with a Cylinder of
ZERO AIR ONLY.
NOTE: Please take special care when performing Calibration of the monitor.
You cannot revert back to the factory setting after any adjustments!
