Bump Test; Preparation - Honeywell Midas S2 User Manual

your local Honeywell Service Representative for further details on calibration services. Testing
should be performed at the end of the sample tube or at the detector with a short length of
tubing. Applying gas with a short length (less than 5 feet/1.5 meters) of clean FEP tubing will
give optimal results for confirming the accuracy and response time of the cartridge.
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. Note that there will be additional transport time due to the
tubing length and conditioning the gas-wet surfaces.
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 would recommend a minimum semi-annual schedule of at
least one bump test per sensor with the appropriate test gas.
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 Gas Table indicates the recommended calibration or bump test gas for the Midas S2 sensor
cartridges:
Consult with your Honeywell Analytics Service Representative for approved methods and
materials before commencing calibrations and bump tests.

6.1.1 Bump test

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.

6.1.2 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 maintenance fault indications on the 4-20 mA loop,
relays or digital outputs. Before starting a test, ensure that suitable steps have been taken to
prevent these indications from triggering unwanted actions. The Midas S2 gas detector has a
special mode for bump testing where the alarm outputs are inhibited.
Midas S2 44 User Manual