D-Guard
2
64
25.
APPENDIX H:
25.1.
Performance Specifications
25.1.1
General Specifications
25.1.2
Methane Detector Specifications
Parameter
Specification
MSS-1
Gas Type
Methane INFRA-RED
MSS-2
Detection ranges
0 – 5% v/v, 0 – 100% v/v
MSS-3
Sensor technology
NDIR Infra-Red
MSS-4
Sensor Size
20mm diameter
MSS-5
Sensor Life
>10 Years
MSS-6
Calibration method
2 point, zero, full-scale
MSS-7
Accuracy (scale and linearity)
To AS2290.3, ANZ60079.29 and AS4641
MSS-8
Stated accuracy temperature limits
0°c to +40°C
MSS-9
Operating temperature limits
-10°C to +40°C
MSS-10
Operating humidity range
0% to 98%
MSS-11
Operating pressure range
80kPa to 120kPa
MSS-12
Humidity/Condensation effects
Negligible
MSS-13
Long term drift
Zero: Less than specified by 60079.29.1
Sens: Less than specified by 60079.29.1
MSS-14
Cross Sensitivity
CO: none. NO: none. H
2
: none
MSS-15
Response time
T90: <=22 seconds
MSS-16
Environmental protection
Replaceable hydrophobic membrane (part of enclosure).
Parameter
Description / Conditions
Limits
Units
Min
Max
GS-1
Measurement Techniques
Electro-Chemical Cell, Infra-Red.
-
-
-
GS-2
Target Gas
Depends upon model (see table 2 – gas types and ranges).
-
-
-
GS-3
Full Scale Ranges
Depends upon model (see table 2 – gas types and ranges).
-
-
-
GS-4
Measurement Accuracy
Refer to Sensor Performance tables.
GS-5
Maximum Loop Current
Under any condition of operation or fault.
-
30
mA
GS-6
Minimum Supply Voltage at 20mA
Minimum operating voltage at detector
13.0
-
VDC
GS-7
Maximum Loop Resistance.
At Vpsu 28V with backlight (see graph).
-
720
Ohms
GS-8
Absolute Maximum Supply Voltage
Maximum supply voltage no damage to electronics (All versions)
-
30
VDC
GS-9
Loop Error Signal (low – electronics fault)
Detected faults within hardware or software
-
3.3
mA
GS-10
Loop Error Signal (low – sensor fault)
IR Head failure
3.3
mA
GS-11
Display
Graphical display 400 pixels by 240 pixels. High contrast type
-
-
-
GS-12
Temperature Sensor
Semiconductor temperature sensor
-20
+110
ºC
GS-13
Pressure sensing – Ambient (optional)
MEMS based absolute value. Instrument body and head.
50
115
kPa
GS-14
Sensor keep-alive battery (optional)
3.6V 55mAH lithium coin cell. PCB mounted ‘encapsulated’
GS-15
Digital Communications
HART 7.0 over 2-wire current loop (refer separate specification)
GS-16
Relays (Optional for non-Ex variants)
2 x Single Pole Change Over for warn and alarm + 1 fault relay
GS-17
Relay max. contact carry current
Non-Switched current handling (Carry Current)
-
10
A
GS-18
Relay maximum contact power
Resistive
1,200
VA
GS-19
Relay contact voltage rating switching).
Switched contact voltage limit
-
240/30
V AC/DC
GS-20
Relay healthy operating state.
Normally energised / Normally de-energised (configurable)
GS-21
Relay state changes
User set Gas Level, system fault.
GS-22
Sounder Output
Sound pressure level
-
98
dB
GS-23
Strobe Output
Flashing or Steady illumination
-
-
-