STATUS SCIENTIFIC CONTROLS
Installation, Commissioning & Routine Gas Testing
FGD4 Gas Detector
TD19/001
Issue:
5
Change Note:
1869
Page 14
6.2.
Test gas
Figure 7 shows a typical arrangement for the application of a certified test
gas.
The purpose of the test gas response check is to confirm that that the
reading on the instrument corresponds with the test gas concentration.
a) If the associated control panel reads correctly then no adjustment is
required.
b) If the above checks are satisfactory then the installation is now
complete.
c) If the instrument does not read correctly then adjustment of the sensor
span setting is required as described in Section 8.1.2. - Sensor Span.
6.2.1.
Gas connection points
Certified test gas is applied directly to the FGD4 via the appropriate
sampling/calibration adaptor.
6.2.2.
Sampling time
Apply the test gas and allow a sufficient time for the sample to reach the gas
detector. The response time will vary according to the length of the sampling
tube.
6.2.3.
Suggested calibration gas levels.
Oxygen sensor:
Zero
N
2
.
Span
20.9 %v/v oxygen balance nitrogen.
Toxic sensor
Zero
Gas free air, must have oxygen.
Span
50 % of measuring range (FSD).
Infrared sensor:
Zero
N
2
.
Span
50 % of measuring range (FSD).
