Table of Contents
Advertisement
OMG100N1.21
7.0
Calibration
7.1
User Calibration
The G100 range of instruments is fully calibrated during manufacture and when returned
for service. However, to improve accuracy between services a user/field calibration can be
performed.
This section sets out the correct procedures to achieve an accurate user calibration.
Note: If the calibration is completed incorrectly it may decrease the accuracy of the
instrument.
Two important terms that are used within this section are "Zero" and "Span".
Zero:
The point at which the instrument is calibrated when there is none of the target
gas present.
Span:
The point at which the instrument is calibrated when a known quantity of the
target gas is present.
7.2
Calibration Gases
User calibration of the instrument will improve the data accuracy in the range of the
calibration gases used. However, it may cause less accurate readings of concentrations
outside this calibrated range. Users should select the correct calibration gas for the
expected gas levels on their particular application. Only use gases with a known certified
gas concentration.
Note: Certified calibration gases can be supplied by Geotech (UK) Limited.
Warning
7.3
Calibration Set-up
The regulator supplied with the calibration kit has been configured to deliver a fixed flow.
It only requires a few turns to open and no adjustment is necessary.
Warning
Page 30
For each gas used the appropriate material safety data sheet
must be read and understood before proceeding. Calibration
gases and the use of pressure regulators can be dangerous.
Exhaust Port
When the instrument is being calibrated, there are two possible
exits for the gas; via the usual manner out of the exhaust port of
the instrument or in cases of over-pressurisation the 1/16
on the pressure relief valve.
It is recommended that both ports have exhaust tubing
attached. The exhaust tubing must emerge in a well-vented
area. Ensure there are no leaks in the tubing and connections.
The calibration should always be carried out in a safe area with
all necessary precautions taken as all pressurised gases are
potentially dangerous.
Copyright Geotechnical Instruments (UK) Limited
G100 Range
"
port
Advertisement
Table of Contents
