MSA Senscient ELDS 1000 series, Operating Manual

Page: 153 / 184

Appendix C – Functional Testing Using Gas
Senscient ELDS™
Rev 15 153
GB
12.3. Testing Cross Duct ELDS Systems with the Refillable Gas Test Cell
Senscient’s Cross Duct ELDS systems are supplied factory calibrated for life and do not require
re-calibration in the field. Where users must undertake response checks with gas, these can be
performed using the Cross Duct Refillable Gas Test Cell.
The Cross Duct Refillable Gas Test Cell comprises a small, Tedlar gas sample bag inside a carrier
that can be inserted into the cell aperture in front of the Receiver of an XD system. Because the
gas bag has flexible walls and becomes inflated when filled with test gas, the total burden of gas
introduced by this cell can vary significantly. Consequently, the Cross Duct Refillable Gas Test
Cell is only suitable for performing a gas detection functionality check (a “bump” test) and cannot
be used to quantify gas response or verify calibration (ELDS systems are factory calibrated-for-life
and do not require calibration checks to be performed.)
The Cross Duct Refillable Gas Test Cell is designed to be filled with 100%V/V methane at
atmospheric pressure. When fully filled and inflated, the walls of the gas bag inside a Gas Test
Cell are approximately 8mm to 12mm apart, which means that the total cell burden will be between
8,000ppm.m & 12,000ppm.m methane.
CAUTION
ONLY the Senscient supplied Cross Duct Refillable Gas Test Cell should be used with Cross
Duct ELDS systems.
VALVE SEAL
CONTROL
CELL INLET
GAS TEST CELL BAG