161 Appendix D
Calibrating Sensors
EVM Series User Manual
Advanced calibration (correction
factors)
CO
2
gas with a 1 Liter/minute flow rate
*NOTE: The range of the CO
2
sensor is 0 to
5,000 ppm. It is recommended to span cal
to the value you will be measuring (i.e.,
4,500 ppm) for best results.
Note settling time with 1 L/min gas flow has
a response time of <90 seconds.
Performed with Pure Air or Nitrogen
*NOTE: Room air can be applied In
clean air environments (such as a
school with no toxic cleaners present).
Isobutylene is used when the VOCs are
unknown.
*NOTE: in order to measure a specific
VOC, you will use the relevant VOC for your
calibrated gas source.
No user cal performed in the field.
(Factory cal. only.)
PID sensor ppb – span: 10 ppm (or
10,000 ppb) of Isobutylene whether the gas
of interest is known/unknown.
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
Performed with Pure Air or Nitrogen
*NOTE: The range of the O
2
sensor is
0 to 30% with a typical span of 20.9%.
Performed with Pure Air or Nitrogen