User Manual - PolyXeta
®
2 Detector with HL Sensor
for Refrigerant Gases - May_2020
Page
7
PolyXeta
is a registered trademark of MSR
Made in Germany
GAPX2_Freon_E_2020_05_18
Phone: +49 8531 9004-0 Fax: +49 8531 9004-54
Specification subject to change without notice
MSR-Electronic GmbH, Buergermeister-Schoenbauer-Str. 13, D 94060 Pocking
www.msr-electronic.de
1.7.5
Listing of Ammonia
MSR code
Freon
type
Calibration
gas
Measuring
range
Relative gas
density
(air =1)
S2125-C
R717
NH
3
1000 ppm
0,59
S2125-F
R717
NH
3
10.000 ppm 0,59
Table 1.2: Available sensor heads for Ammonia
2
General Description
2.1
Device Description
The fixed gas detector type "PX2" consists of a sensor head and an I/O unit.
The series
PX2-1
is approved according to ATEX and IECEx certified for zone 1 and 2.
The series
PX2-2
is certified by the manufacturer
’
s ATEX declaration conformity for zone 2.
The sensor head consisting of the gas sensor and the evaluation, calibration and diagnostic electronics
is an independent unit in flameproof stainless-steel housing (Ex d) with an external thread NPT ¾ ".
All sensor data are stored in the sensor head. After the end of the calibration period or at the end of
the sensor lifetime, the sensor can easily be replaced by a calibrated or a new sensor head.
The I/O unit including the operating power supply communicates with the sensor head via the internal
local bus, monitors the communication and translates the measured value of the sensor head into a 4-
20 mA signal. The value of the gas concentration and other relevant data and status messages are
available on the central bus. The alarm relay is activated when the alarm threshold is exceeded. In
case of a fault the fault relay and the analog output change into fault state and the fault message is
transmitted via the central bus. An optional display unit with indication of the measurement values
and status LEDs can be integrated behind a viewing window. The I/O unit is installed in a flameproof
(Ex db for PX2-1, Ex nA for PX2-2) die-cast housing with up to four openings with NPT ¾ " female
threads according to standard ANSI B1.20.1 for receiving sensor head and cable glands.
2.2
Measurement Principles
See chapter 10
“
Sensor Specification
”
.
