Sensitron SMART3G-GrI, Instruction Manual

Page: 25 / 44

ENGLISH
Pag. 21
1.2 Gas detectors identification
The detector part number consists of an initial S, followed by 4 identification numbers of the
sensor code, and two final letters that describe the gas detected.
1.3 Technical specifications
Sensing element Pellistor (Catalytic sensor), IR sensor or electrochemical cell
sensor
Measurement range Methane 0-100% LFL (according to ISO/IEC 80079-20-1: 2017)
Oxygen 0-25% V/V
Carbon monoxide 0-500 ppm
Predicted sensor lifetime 4/5 years (catalytic or IR sensor)
2/3 years (electrochemical cell)
Power supply 12- 24 Vdc - 20% + 15%
Maximum power <5,4 W (see instrument label)
Control unit Microprocessor 10 bit
Watch-dog Internal and external for the microprocessor status control
Visual indications Flashing LED on the base board; The display version has with 9
smart LEDs and 4 digits
Proportional output with
pin 5-6 of JP9 closed
4-20 mA (default)
3 mA under scale alarm
2 mA fault
Proportional output with
pin 5-6 of JP9 open
4-20 mA
2 mA fault
22 mA overrange alarm
Max load resistance 200 Ω
Serial outpur (optional) RS485 for MU+ and SENTOX IDI control panels
ME = METHANE
O2 = OXYGEN
CO = CARBON MONOXIDE
OTHER GAS AVAILABLE ON
REQUEST
s
GAS DETECTOR TYPE
GAS NAME
signed to prevent the effects of transients, which may cause instability or incorrect
readings with possible false alarms.
³
Hysteresis cycle applied to the digital outputs to eliminate continuous switching close
to the preset alarm thresholds.
³
Watch-dog for the microprocessor control. In case of intervention, the output current
drops down to 0mA while the red LED stops blinking and remains on. If the RS485 in-
terface is connected, the communication will be interrupted, while if the 3-relay card is
plugged in, the Fault relay will activate.
Table 1) Technical specifications of SMART3G-GrI gas detectors