Thermo Fisher Scientific
Model 410
i
Instruction Manual
4-1
Chapter 4
Calibration
This chapter describes the procedures for performing a standard zero/span
calibration and a multipoint calibration of the Model 410
i
. The
information described here is more than adequate to perform the
calibration. However, if greater detail is needed, please refer to the
Quality
Assurance Handbook for Air Pollution Measurement Systems
1
.
The following sections discuss the required apparatus and procedure for
calibrating the instrument.
The following equipment is required to calibrate the instrument:
A cylinder of CO
2
in air containing an appropriate concentration of CO
2
suitable for the selected operating range of the analyzer under calibration is
necessary. The assay of the cylinder must be traceable either to a National
Institute of Standards and Technology (NIST) CO
2
in Air Standard
Reference Material (SRM) or an NIST/EPA approved gas manufacturer's
Certified Reference Material (CRM).
A recommended protocol for certifying CO
2
gas cylinders against a CO
2
,
SRM or CRM is given in the
Quality Assurance Handbook
1
. The CO
2
gas
cylinder should be recertified on a regular basis determined by the local
quality control program.
Calibration requires zero air that is free of contaminants which will cause a
detectable response on the CO
2
analyzer. The zero air should contain <0.5
ppm CO
2
.
Depending on the grade, zero air as supplied in cylinders from commercial
suppliers typically contains CO
2
concentrations in the 0.1 to 400 ppm
range. So cylinder zero air should be scrubbed of the residual CO
2
prior to
its use in the instrument as a dilution gas or a zero standard.
It is also possible to use a zero air generator in place of zero air cylinders.
Zero air generation is a three-step process involving:
Equipment Required
CO
2
Concentration
Standard
Zero Air Generator
