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Safety Instructions
Memosens ISFET pH sensors
pH measurement
Supplement to BA02154C
Safety instructions for electrical apparatus inexplosion-hazardous areas
NEPSI Ex ia IIC T3/T4/T6 Ga
NEPSI Ex ia IIC T4/T6 Ga

Memosens ISFET pH sensors

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Memosens ISFET pH sensors
pH measurement
Table of contents
Associated documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Additional documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Temperature tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Endress+Hauser

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Memosens ISFET pH sensors

Associateddocumentation

This document is an integral part of Operating Instructions BA02154C.

Additional
documentation

Competence Brochure CP00021Z• Explosion Protection: Guidelines and General Principles• www.endress.com

Certificates

NEPSI certificate of conformity, certificate number: GYJ19.1375XIdentification

The nameplate provides you with the following information on yourdevice:• Manufacturer identification• Order code
• Extended order code
• Serial number• Safety information and warnings• Ex marking on hazardous area versions‣ Compare the information on the nameplate with the order.
Type code
Item type

VersionxPS47E
xPS77ENAx = C, OC
NEPSI Ex ia
No Ex relevance IIC
T3/T4/T6Ga****c+*c indicates the shaft length (≤ 600 mm (23.6 in) no Exrelevance)

Item type

VersionxPS97E

NAx = C, OCNo Exrelevance

NEPSI Ex ia c indicates the shaft length (≤ 600 mm (23.6 in) no Ex
IIC T4/T6relevance)Ga****c+*

Certificates and approvals
Ex approvals
The Memosens ISFET pH sensors, type CPSxE, have been certified by
the National Supervision and Inspection Centre for Explosion Protection
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Memosens ISFET pH sensors

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and Safety of Instrumentation (NEPSI). These products meet thefollowing standards:• GB 3836.1-2010 Explosive atmospheres-Part 1: Equipment-General
requirements• GB 3836.4-2010 Explosive atmospheres-Part 4: Equipment
protection by intrinsic safety "i"• GB 3836.20-2010 Explosive atmospheres-Part 20: Equipment withequipment protection level (EPL) Ga
CPS47E / CPS77E:
NEPSI Ex ia IIC T3/T4/T6 Ga
CPS97E:NEPSI Ex ia IIC T4/T6 Ga

SafetyInstructions

The inductive Memosens ISFET pH sensors CPS47E, CPS77E, CPS97E
are suitable for use in hazardous areas in accordance with:NEPSI certificate GYJ19.1375X• It is not permitted to operate the sensor under electrostatically criticalprocess conditions. Significant vapor and dust clouds, which have adirect impact on the Memosens sensor head, must be avoided.
• The sensors must not be operated under process conditions where
the sensor and the connection system can become electrostaticallycharged. Sensor operation in liquid media that are in contact with theprocess and have a minimum conductivity of 10 nS/cm is notconsidered problematic with regard to electrostatic charge.
• Ex-protected digital sensors with Memosens technology areidentified by an orange-red ring on the terminal head.

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Memosens ISFET pH sensors• The procedures for electrical connection described in the OperatingInstructions must be followed.
• In order to maintain and guarantee the explosion protection of thedevice, the user may not modify the configuration in any way. Everychange can compromise the safety of the device.
• The end user must adhere to the Operating Instructions and thefollowing standards for the installation, operation and maintenanceof the product:• GB 50257-2014 "Code for construction and acceptance of electric
device for explosion atmospheres and fire hazard electricalequipment installation engineering".
• GB 3836.13-2013 "Explosive atmospheres - Part 13: Equipmentrepair, overhaul and reclamation"• GB/T 3836.15-2017 "Explosive atmospheres - Part 15: Electricalinstallations design, selection and erection"• GB/T 3836.16-2017 "Explosive atmospheres - Part 16: Electricalinstallations inspection and maintenance"• GB/T 3836.18-2017 "Explosive atmospheres - Part 18: Intrinsicallysafe electrical systems"
The correlations between the device model, the temperature class, theprocess temperature range and the ambient temperature range areindicated in the temperature tables .

Temperaturetables

SensorTemperatureclass

CPS47E T3
CPS77E
T4T6CPS97E T4

T6

Process temperature Tp

Ambient temperature Ta

minimum

minimum

maximum

maximum–15 °C (5 °F) 135 °C (275 °F) –15 °C (5 °F) 70 °C (158 °F)–15 °C (5 °F) 115 °C (239 °F) –15 °C (5 °F) 75 °C (167 °F)
110 °C (230 °F)

80 °C (176 °F)

100 °C (212 °F)

85 °C (185 °F)

90 °C (194 °F)

90 °C (194 °F)–15 °C (5 °F) 65 °C (149 °F)–15 °C (5 °F) 65 °C (149 °F)–15 °C (5 °F) 110 °C (230 °F) –15 °C (5 °F) 80 °C (176 °F)
100 °C (212 °F)

85 °C (185 °F)

90 °C (194 °F)

90 °C (194 °F)–15 °C (5 °F) 65 °C (149 °F)–15 °C (5 °F) 65 °C (149 °F)

The temperature table above applies only under the following
installation conditions, which are described in the following graphic→  8. If the installation conditions cannot be met, the maximum
process temperature Tp must not exceed the maximum ambient
temperature Ta.
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Connection

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Ex specification• The CPSx7E-type ISFET pH sensors are approved in accordance withNEPSI certificate GYJ19.1375X and are suitable for use in hazardousenvironments.
• The approved digital ISFET pH sensors feature an intrinsically safe
input with the following parameter set:Parameters

Value

Pi

180 mW

The approved CPSx7E-type digital ISFET pH sensors must be connected
to a Memosens measuring cable with an intrinsically safe output withthe following parameter:

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Parameters

Value

Po

Maximum 180 mW

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Installationconditions

4> 37 (1.46)

21

3A0041281

1
12
348

Installation conditions
Limit
Distance between plug-in head (lower edge) and process medium, without
ring and thrust collar
Process temperature Tp
Ambient temperature Ta

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