MSA Senscient ELDS 1000 series, Operating Manual

Page: 111 / 184

Functional Testing
Senscient ELDS™
Rev 15 111
GB
Comparing the gas quantity calculated by the Receiver to the quantity of SimuGas simulated by
the Transmitter provides a powerful means of verifying the correct function of an ELDS OPGD.
SimuGas™ OPGD functionality testing offers considerable advantages over conventional OPGD
testing methodologies, including the following:-

There is no need for operators to generate, handle or apply hazardous gases to detectors in
the field.

There is no need for operators to gain direct physical access to detectors in order to test them.
Commands to perform SimuGas tests can be sent remotely from wherever it is convenient, and
the results of tests can be monitored remotely too.

Because SimuGas is simple, quick and convenient it makes it possible to functionally test gas
detectors much more frequently, improving the safety integrity of a fixed gas detection system.

SimuGas™ Auto performs an automatic ELDS gas detector functionality test every 24 hours
and the results of this testing are stored in the Receiver’s Event Log.

The operation and maintenance costs for a fixed gas detection system are considerably
reduced.
Because of the flexibility afforded by SimuGas™ technology it is possible to perform functional
testing of ELDS OPGDs in a number of different ways which are described in the following
sections.
5.2. SimuGas™ Auto
The simplest way for users to realise the considerable safety integrity benefits provided by
SimuGas™ technology is to make use of SimuGas™ Auto automated ELDS gas detector
functionality testing that is a standard feature of ELDS systems. As standard, ELDS Transmitters
perform a SimuGas Auto test with a known SimuGas level every 24 hours, with the Receiver
opposite checking to confirm that each test produces acceptable results. In the unlikely event that
a SimuGas Auto test does not produce acceptable results, the Receiver is configured to signal a
Fault to the control system, providing an early warning about any potential problem with the ELDS
OPGD system affected.
Compared to conventional OPGD testing methodologies or operator-initiated SimuGas tests,
SimuGas Auto has the following advantages:

Testing is performed without the gas detector being visited by operators.

Testing is performed every 24 hours, providing far earlier diagnosis of any problem than tests
relying upon operators visiting gas detectors.

Testing requires no additional cabling, software or control system infrastructure. SimuGas Auto
can be employed successfully using the same wiring and control systems that were used with
earlier generations of gas detectors.