Midas
®
Gas Detector
17-3
Applying gas at the end of the installed sample
line will test the full system including the whole
length of tubing. This will verify the integrity of the
tubing. Sample line integrity can also be checked
by performing a leak check (see section 8.5). Note
that there will be additional transport time due to the
tubing length and conditioning the gas-wet surfaces
(see table 4-1).
Bump tests are also used as an approximate means
to present a controlled gas release to the sensor
cartridge in order to verify that the transmitter does
respond accordingly. Bump testing is popular as
typical experiences show that a smaller list of easier
to handle gases can be used to provide functional
tests on a wider range of gas types. In the absence
of a formal calibration policy from the end user,
Honeywell Analytics would recommend a minimum
semi-annual schedule of at least one bump test
per sensor with the appropriate test gas (see details
below).
Bump testing may reduce sensor cartridge lifetime
and the accuracy of the calibration if applied
incorrectly or too frequently. Use only the target gas
or the recommended bump test gas.
Zero calibration is a recommended procedure
that should be performed periodically to improve
the performance of the sensor. This is particularly
important when the sensor is operating outside of
normal environmental conditions (20°C, 50% rH).
The tables in
Appendix B
indicate the recommended
calibration or bump test gas for the Midas
®
sensor
cartridges:
Consult with your Honeywell Analytics Service
Representative for approved methods and materials
before commencing calibrations and bump tests. See
Tech Note 1998-0219
Protocol for Testing Toxic Gas
Detectors for additional information.
Bump the Testing Midas
®
Gas Detector
A bump test is not intended to be an accurate
calibration, but is used as a confidence check to
ensure that the gas detection system is functional.
Since some of the target gases are difficult to handle,
bump testing often makes use of cross sensitivities
so that more convenient gases can be used. In bump
test mode, the Modbus/TCP outputs are not inhibited.
Only the 4-20 mA and alarm outputs are inhibited.
The bump gas test is a functional check only. Consult
local guidelines for recommended best practices.
Bump test concentrations are calculated to generate
a minimum first alarm level response.
Equipment
See Tech Note 1998-0219
Protocol for Testing Toxic
Gas Detectors for additional information. These items
are required:
• Test gas (see
Appendix B
)
• Special regulator for extractive use (if using field
calibration cylinder) or suitable sample bag (if not
sampling directly from cylinder)
• Tubing (suitable for gas being applied)
Preparation
Most of the test gases are highly toxic. It is essential
that personnel using these toxic gases be trained in
their use. Ensure that the test gas will be vented safely.
Applying test gas may cause alarm, fault or
Summary of Contents for Midas
Page 7: ...Midas Gas Detector 1 1 1 Description ...
Page 9: ...Midas Gas Detector 2 1 2 Overview ...
Page 14: ...Midas Gas Detector 3 1 3 Default Configuration ...
Page 17: ...Midas Gas Detector 4 1 4 Installation ...
Page 41: ...Midas Gas Detector 5 1 5 Startup ...
Page 43: ...Midas Gas Detector 6 1 6 Operation ...
Page 53: ...Midas Gas Detector 7 1 7 Navigating Modes and Submenus ...
Page 74: ...Midas Gas Detector 8 1 8 Maintenance ...
Page 82: ...Midas Gas Detector 9 1 9 Pyrolyzer Module Options ...
Page 89: ...Midas Gas Detector 10 1 10 Optional LonWorks Interface Installation ...
Page 99: ...Midas Gas Detector 11 1 11 Troubleshooting and Fault Diagnosis ...
Page 102: ...Midas Gas Detector 12 1 12 REFLEX ...
Page 104: ...Midas Gas Detector 13 1 13 Internal Web Server ...
Page 106: ...Midas Gas Detector 13 3 Diagram 13 1 IPAddress setting in Windows XP ...
Page 129: ...Midas Gas Detector 14 1 14 Typical Installation Topologies ...
Page 132: ...Midas Gas Detector 15 1 15 Ordering Information ...
Page 136: ...Midas Gas Detector 16 1 16 Specifications ...
Page 139: ...Midas Gas Detector 17 1 17 Calibration and Bump Testing ...
Page 143: ...Midas Gas Detector A 1 A Modbus TCP Interface ...
Page 150: ...Midas Gas Detector B 1 B Gas Tables ...
Page 158: ...Midas Gas Detector C 1 C Warranty ...