Calibration; Calibration Introduction; Frequency Of Calibration-Best Practice - LANDTEC GEM5000 Operating Manual

GEM5000 gas analyzer

9 Calibration

9.1 Calibration introduction

The GEM5000 gas analyzer is carefully calibrated at time of manufacturer and when
returned for service. However, it is desirable to be able to carry out a calibration process
between services.
This section outlines the correct procedures to enable the field technician to field calibrate
the gas analyzer.
Note: This does not replace the factory service and calibration. If this calibration is
completed incorrectly it may decrease the accuracy of the gas analyzer.
CH CO and O can be measured by all GEM5000 gas analyzer models as a standard;
4, 2 2
these channels can be user calibrated. Optionally, the analyzers can have other gas
channel specified at purchase; these channels can be calibrated as well. This section will
describe in detail how to calibrate the three standard gas channels plus the CO channel.
The GEM5000 instrument can have a H
that H is used in the calibration process and is also set out within this section. Refer to
2
section 4.2 GEM5000 Part Number Legend to determine if you have an H
CO channel. While H2 is used for calibration of the compensated CO cell, it is not a gas
that is measured by the instrument as a part of a reading. As such it only appears on the
gas check and View Data screens but not the reading screen.
For the other gas channel options contact LANDTEC for advice.
Two important terms that are used within this section are 'Zero' and 'Span'.
Zero: The point at which the gas analyzer is calibrated when there is none (Zero
percent or ppm) of the target gases present.
Span: The point at which the gas analyzer is calibrated when a known quantity of the
target gas is present.
9.2 Frequency of calibration
The GEM5000 gas analyzers can be checked against a known concentration of gas, to
give confidence that the analyzer is operating as expected at the time and conditions in
which it is being used.
temperature changes by more than 20° Fahrenheit over the course of a monitoring since
the last field calibration.
It is recommended that the instrument is regularly serviced and calibrated by LANDTEC.
Please refer to the instrument's calibration certificate for the last date of calibration.
When defining the frequency of user calibration, the following are factors to be
considered:
 The frequency of use of the analyzer. (daily?/monthly?)
 The level of confidence and accuracy required for readings to be taken.
 Historical user calibration data.
 Site specific requirements or conditions.
 Historical understanding of expected readings on site.
LANDTEC
©
compensated CO channel. This option requires
2
—
best practice.
A field calibration should be performed if the ambient
5K-MNL-GEM5000
compensated
2
Page 93