7
Version 2.1
Update: April 2016
PONSEL Mesure
– Aqualabo Contrôle
35 Rue Michel Marion
– 56850 CAUDAN, FRANCE
Tel.: +33(0)2 97 89 25 30
– Fax: +33(0)2 97 76 55 72
2.2.2 PHEHT sensor: pH and temperature.
This PONSEL sensor is fitted with an Ag/AgCl reference electrode, used to measure pH and redox, in
a "PLASTOGEL"® KCl-saturated plasticized electrolyte.
The Plastogel® electrolyte is in direct contact with the external environment without interposition of
capillary or porous material. There is therefore no risk of fouling or deactivating the reference
electrode.
The electrode used to measure the pH is a pH-sensitive glass bulb (made from special glass) welded
to the end of a crystal tube, and the electrode for Redox measurements is a platinum disk.
Temperature: measured by an NTC thermistor inserted in a stainless steel sheath.
pH measurement
Measurement principle (pH)
pH/reference combined electrode: special glass,
Ag/AgCI reference. Gel (KCI) electrolyte
Measurement range
0
– 14 pH
Resolution
0.01 pH
Accuracy
+/- 0.1 pH
Measurement of the Redox
Measurement principle (Redox)
Redox/reference combined electrode: Platinum disk,
Ag/AgCI reference. Gel (KCI) electrolyte
Measurement range
- 1000.0 to + 1000.0 mV
Resolution
0.1 mV
Accuracy
2 mV
Response time
< 5 s
Temperature measurement
Measurement principle (T°C)
NTC thermistor
Operating temperature
0.00 °C to + 50.00 °C
Resolution
0.01 °C
Accuracy
0.5 °C
Response time
< 5 s
Storage temperature
0 °C to + 60 °C
Ingress protection rating
IP 68
Signal interface
Modbus RS-485 as standard and SDI-12 as an
option
Measurement refresh rate
< 1 second maximum
Power supply for sensor
5 to 12 volts
Power consumption
Standby: 25 µA
When sending via RS-485 (1 measurement/second):
3.9 mA
When sending via SDI-12 (1 measurement/second):
6.8 mA
Current pulse: 500 mA
Sensor
Dimensions of fitted sensor
Lower part: 21 mm in diameter; 92 mm long,
Upper part: 27 mm in diameter; 103 mm long,
Length of fitted sensor: without cable gland 210 mm;
Length with cable gland: 260 mm.
Weight
350 g ( cable)
Material in contact with the medium
PVC, POM-C, special pH glass, platinum,
polyurethane
Maximum pressure
5 bar
Cable/connection hardware
9-wire shielded conductor, uncoated-strand
polyurethane sleeve
