Automatic Self-Test; Sensor Functionality Check; Output Options - Emerson GDU-Incus Reference Manual

Reference Manual
00809-0100-3003, Rev AA
Figure 4-4
pressure relief valve. Noise 1 represents a pressure relief valve actuating for approximately 13 seconds
before a leak (noise 2) occurs. The detector starts the delay time when the pressure relief valve opens
and continues to monitor for leaks. If a leak occurs during a spurious noise spike the delay time will be
reduced by the duration of the spurious noise spike.
It is important that all spurious noise spikes of significant duration within the detector coverage are
identified. It is recommended that the alarm delay is set to a value greater than the maximum spurious
noise spike operating duration. If two or more spurious noise sources are situated within the detector
coverage area, it is recommended to assess whether activation of these sources can overlap in time, in
which case the delay time should be extended accordingly.
4.1.3

Automatic self-test

The automatic self-test checks the complete detector every 320 ms by sending an electrical signal of
known amplitude through the sensing circuitry and analyzing the result, without interrupting the
normal functionality of the sensor. If drift, component failure or damage occurs a fault is signaled, refer
to section 4.6.
4.2

Sensor functionality check

The sensors on the GDU-Incus are factory calibrated and do not require adjustment. Before operation
functionality checks are recommended to ensure correct installation. On power-up, the GDU-Incus will
perform a diagnostic check to ensure all main functions are operational, and continuously monitors the
sensors via the built in self-test.
Sensor functionality can be checked in two ways;
•
GDU-Incus handheld series test transmitter sound source. Ensure that the background ultrasonic
level is suitable for the distance of proposed test transmitter test. Aim the transmitter at the sensor
face from a known distance, The GDU-Incus display dB level will rise according to the hand held
device used and distance. Check all four (4) sensors, if possible, by moving around the detector and
repeating.
•
Test verification kit – a pressurised gas release of a known pressure and size at a known distance.
The GDU-Incus display level will rise according to the size, pressure, and distance used.
4.3

Output options

The GDU-Incus comes with most industry standard forms of communication as standard. This enables
the detector to be operated as part of a system, a standalone unit, or hard wire linked to form a sub
network.
shows detector response when a leak is encountered during a spurious noise spike such as a
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