Det-Tronics GTS Sensor Module SAFETY MANUAL - Manual (Page 2)

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DESIGN
The GT3000 Electrochemical Gas Detector is an
intelligent stand-alone industrial gas detector, designed
to provide continuous monitoring of the atmosphere for
hazardous gas leaks or oxygen depletion. The GT3000
Gas Detector consists of a replaceable sensor module
(Model GTS) connected to a transmitter module (Model
GTX). The GT3000 is a 2-wire device that generates a
4-20 mA output signal with HART communication that is
proportional to the concentration of the target gas. The
GT3000 is compatible with FlexVu® Model UD10 and
UD20 Universal Display Units, as well as other devices
that are able to monitor a linear 4-20 mA dc signal. All
alarm functions are provided by the monitoring device.
The GT3000 is classified as Type B smart element
according to IEC61508. The GT3000 contains self-
diagnostics and sends the current output to a specified
failure state upon internal detection of a failure (see
GT3000 instruction manual for details).
Safety-Certification of the GT3000 Series
Electrochemical Toxic Gas Detector includes:
• the 4-20 mA output of the GTX in combination with
H
2
S or O
2
GTS modules.
Non-Interfering outputs
Safety Certification of the GT3000 includes the following
non-interfering outputs:
- LEDs and magnetic switches
- HART communication
- Display via UD20*
The HART communication protocol is non-interfering
and is to be used for diagnostics within the SIL 2
safety loop in the Safety operation mode. Diagnostics
are defined as read only information. Local HART
communication with the GT3000 using a handheld
HART field communicator, or AMS program connected
to the 4-20 mA output, is acceptable. Proper analog
signal loop resistance must be installed as documented
in the instruction manual to enable local HART
communication.
*The UD20 has been evaluated as a non-interfering
loop-powered device and is approved for use in-line
with a Safety-Certified GT3000. The GT3000 comes
with one of two pre-programmed fault output levels:
2.45 mA or 3.6 mA. The UD20 must only be used in
conjunction with 3.6 mA fault level GT3000 versions.
VALID INPUT RANGE
GT3000 fault annunciation is provided on the 4-20
mA signal output loop by signaling to a specific mA
current output level. The receiving device must be
programmed to indicate a fault condition when current
levels reach under-current of 3.6 mA or less or over-
current of 21 mA or more.
NOTE
The GT3000 analog signal is not safety-rated
during detector warm-up or calibration mode.
Alternative means should be used at the job site
to ensure facility safety during these activities.
DIAGNoSTIC RESPoNSE TIME
The GT3000 will perform all critical diagnostic functions
within one hour, worst case diagnostic detection time.
CERTIFICATIoN
The GT3000 Safety-Certified version is certified by
exida ® to IEC61508 for single input use in low demand,
SIL 2 Safety Instrumented Systems.
SAFETY-CERTIFIED PRoDUCT IDENTIFICATIoN
Safety Certification of all GT3000 models meeting SIL
2 safety standards is clearly identified on the product
label.