Mettler Toledo InPro 6950 Instruction Manual

InPro 6950 Series O2Sensors

Instruction manual Bedienungsanleitung Instructions d’utilisation

InPro 6950 52 206 137

2 InPro 6950 Series O2Sensor 12 mm

InPro 6950 © 02 /17 Mettler-Toledo GmbH 52 206 137 Printed in Switzerland

English Page 3

Deutsch Seite 38

Français Page 73

InFit, InPro, ISM, and InTrac are registered trademarks of the Mettler Toledo Group in Switzerland and a further twelve countries.

InPro 6950 Series O2Sensor 12 mm 3

InPro 6950 Series O2Sensors

Instruction manual

4 InPro 6950 Series O2Sensor 12 mm

InPro 6950 © 02 /17 Mettler-Toledo GmbH 52 206 137 Printed in Switzerland

1 Introduction................................................................5

2 Important notes ..........................................................6

2.1 Notes on operating instructions .....................................6

2.2 Intended use ...............................................................6

2.3 Safety instructions........................................................7

2.4 Examples of some typical applications...........................8

2.5 Use in Ex-zones...........................................................8

2.6 Ex-classification ATEX ..................................................8

2.6.1 Introduction.................................................................8

2.6.2 Rated data ..................................................................9

2.6.3 Special conditions......................................................10

2.7 Ex-classification FM approved.....................................11

3 Product description...................................................12

3.1 General information....................................................12

3.2 Principle ...................................................................12

3.3 Scope of delivery .......................................................13

3.4 Equipment features ....................................................14

4 Installation...............................................................15

4.1 Mounting the sensor...................................................15

4.2.1 Connecting the InPro 6950 to a VP cable .....................15

4.2.2 Connecting the VP cable to the transmitter ....................16

5 Operation.................................................................17

5.1 Start-up and polarizing...............................................17

5.2 Calibration ................................................................18

5.2.1 Purpose of calibration ................................................18

5.2.2 What you have to know for calibration .........................18

5.2.3 Single point calibration...............................................19

5.2.4 Dual point calibration.................................................19

6 Maintenance ............................................................20

6.1 Inspection of the sensor..............................................20

6.1.1 Visual inspection .......................................................20

6.1.2 Testing the METTLER TOLEDO O

2

sensor master

InPro 6950...............................................................21

6.1.3 Testing the sensor via a transmitter..............................22

6.2 Changing the electrolyte, the membrane body

or the interior body.....................................................23

7 Storage....................................................................27

8 Product specification ................................................28

8.1 Certificates ................................................................28

8.2 Specifications............................................................29

9 Ordering information.................................................30

9.1 Sensors ....................................................................30

9.2 Accessories...............................................................30

9.3 Spare parts ...............................................................30

9.4 Recommended transmitters.........................................31

9.5 Recommended housings ............................................31

10 Theory of the polarographic sensor ............................32

10.1 Introduction...............................................................32

10.2 Principle of the design of an oxygen electrode ...............33

10.3 Parameters determining current ...................................34

10.4 Polarization voltage ...................................................35

10.5 Temperature..............................................................35

10.6 Dependence on flow...................................................35

10.7 Oxygen partial pressure – oxygen concentration ............36

Contents

InPro 6950 Series O2Sensor 12 mm 5

1 Introduction

Thank you for buying the InPro®6950 sensor from METTLER TOLEDO.

The construction of the InPro 6950 sensors employs leading edge tech nology and complies with safety regulations currently in force. Notwithstanding this, improper use could lead to hazards for the user or a third-party, and/or adverse effects on the plant or other equipment.

Therefore, the operating instructions must be read and understood by the persons involv ed before work is started with the sensor.

The instruction manual must always be stored close at hand, in a place accessible to all people working with the InPro 6950.

If you have questions, which are not or insufficiently answered in this instruction manual, please contact your METTLER TOLEDO supplier. They will be glad to assist you.

6 InPro 6950 Series O2Sensor 12 mm

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2 Important notes

2.1 Notes on operating instructions

These operating instructions contain all the information needed for safe and proper use of the InPro 6950 sensor. The operating instructions are intended for personnel entrusted with the operation and maintenance of the sensors. It is assumed that these persons are familiar with the equipment in which the sensor is installed.

Warning notices and symbols

This instruction manual identifies safety instructions and additional information by means of the following symbols:

This symbol draws attention to safety instructions and warnings of potential danger which, if neglected, could result in injury to persons and/or damage to property.

This symbol identifies additional information and instructions which, if neglected, could lead to defects, inefficient operation and possible loss of production.

2.2 Intended use

METTLER TOLEDO InPro 6950 sensors are intended solely for inline measurement of the oxygen partial pressure in liquids and gases, as described in this instruction manual.

Any use of these sensors which differs from or exceeds the scope of use described in this instruction manual will be regarded as inappropriate and incompatible with the intended purpose.

The manufacturer/supplier accepts no responsibility whatsoever for any damage resulting from such improper use. The risk is borne entirely by the user/ operator.

Other prerequisites for appropriate use include: – compliance with the instructions, notes and

requirements set out in this instruction manual.

– acceptance of responsibility for regular inspection,

maintenance and functional testing of all asso ci ated components, also including compliance with local operational and plant safety regulations.

– compliance with all information and warnings

given in the documentation relating to the products used in conjunction with the sensor (housings, transmitters, etc.).

– observance of all safety regulations governing the

equipment in which the sensor is installed.

InPro 6950 Series O2Sensor 12 mm 7

– correct equipment operation in conformance with

the prescribed environmental and operational conditions, and admissible installation positions.

– consultation with Mettler-Toledo Process Analytics

in the event of any uncertainties.

2.3 Safety instructions

– The plant operator must be fully aware of the

potential risks and hazards attached to operation of the particular process or plant. The operator is responsible for correct training of the workforce, for signs and markings indicating sources of possible danger, and for the selection of appropriate, stateof-the-art instrumentation.

– It is essential that personnel involved in the

commissioning, operation or maintenance of these sensors or of any of the associated equipment (e.g. housings, transmitters, etc.) be properly trained in the process itself, as well as in the use and handling of the associated equipment. This includes having read and understood this instruction manual.

– The safety of personnel as well as of the plant

itself is ultimately the responsibility of the plant operator. This applies in particular in the case of plants operating in hazardous zones.

– The oxygen sensors and associated components

have no effect on the process itself and cannot influence it in the sense of any form of control system.

– Maintenance and service intervals and schedules

depend on the application conditions, composition of the sample media, plant equipment and signi ficance of the safety control features of the measuring system. Processes vary considerably, so that schedules, where such are specified, can only be regarded as tentative and must in any case be individually established and verified by the plant operator.

– Where specific safeguards such as locks, labels,

or redundant measuring systems are necessary, these must be provided by the plant operator.

– A defective sensor must neither be installed nor

put into service.

– Only maintenance work described in this operat-

ing instruction may be performed on the sensors.

– When changing faulty components, use only

original spare parts obtainable from your METTLER TOLEDO supplier (see spare parts list, “Section 9.3”).

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– No modifications to the sensors and the acces-

sories are allowed. The manufacturer accepts no responsibility for damages caused by unauthorised modifications. The risk is borne entirely by the user.

2.4 Examples of some typical applications

Below is a list of examples of typical fields of application for the oxygen sensors. This list is not exhaustive.

Measurement in liquids:

– Brewing – Beverage filtration – Filling stations

Measurement in gases:

– CO

2

recovery

– CO

2

purity – Product storage – Inert production

2.5 Use in Ex-zones

Attention!

For an installation in Ex-zones please read the guidelines following hereafter:

1258

Ex-classification ATEX:

Ex ia IIC T6/T5/T4/T3 Ga/Gb Ex ia IIIC T69°C/T81°C/T109°C/T161°C Da/Db

Number of the test certificate:

SEV 14 ATEX 0169 X IECEx SEV 14.0026X

Ex-classification FM approved:

IS/ I, II, III /1/ABCDEFG / T6 Ta =60 °C

- 53 800 002; Entity

2.6 Ex-classification ATEX

2.6.1 Introduction

According to Directive 94/9/EC (ATEX 95) Appendix I, the O

2

oxygen sensors type InPro 6XXX is a devices of equipment group II, category 1/2G which, according to Directive 99/92/EC (ATEX 137) can be used in zones 0/1 or 1/2 or 1 or 2 as well as gas groups IIA, IIB and IIC, which are potentially explosive due to combustible substances in the temperature T3 to T6.

The requirements specified in EN 60079-14 must be observed during use / installation.

InPro 6950 Series O2Sensor 12 mm 9

According to Directive 94/9/EC (ATEX 95) Appendix I, the O2oxygen sensors type InPro 6XXX is a devices of equipment group II, category 1/2D which, according to Directive 99/92/EC (ATEX 137) can be used in zones 20/21 or 21/22 or 21 or 22, which are potentially explosive due to combustible dust.

The requirements specified in EN 60079-14 must be observed during use / installation.

For the analog version of the O

2

oxygen electrode, the O2measurement circuit, temperature measurement circuit and data chip circuit are part of the common intrinsically safe system and are jointly connected to and operated by a separately certified transmitter.

The digital version of the O

2

oxygen sensor is connected to and operated by two-wire cable to the certified transmitter.

The intrinsically safe circuits are galvanically isolated from the non-intrinsically safe circuits up to a nominal voltage peak value of 375 V and from the earthed parts up to a nominal voltage peak value of 30 V.

2.6.2 Rated data

Analog O

2

Oxygen sensor

With type of protection: intrinsic safety to Ex ia IIC

O

2

measuring circuit, temperature measuring

circuit and data chip circuit

Only for connection to certified intrinsically safe circuits. Maximum values: Ui≤ 16 V, Ii≤ 190 mA, Pi≤ 200 mW Li= 0 (effective internal inductance) Ci= 900 pF (effective internal capacitance)

The values above apply, each as the sum of all the individual circuits of the associated intrinsically safe supply and evaluation unit (transmitter).

Digital O

2

Oxygen sensor

With type of protection: intrinsic safety to Ex ia IIC

Two-wire current circuit

Only for connection to certified intrinsically safe circuits. Maximum values: U

i

≤ 16 V, Ii≤ 30 mA, Pi≤ 50 mW Li= negligible Ci= negligible

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2.6.3 Special conditions

– The relationship between the maximum permissi-

ble ambient or media temperature and temperature class, for category 1G applications, zone 0, is shown in the following table:

Temperature class Max. ambient or

media temperature

T 6 68 °C T 5 80 °C T 4 108 °C T 3 160 °C

– The relationship between the maximum permissi-

ble ambient or media temperature and temperature class, for category 1D applications, zone 20, is shown in the following table:

Temperature class Max. ambient or

media temperature

T 69 °C 68 °C T 81 °C 80 °C T 109 °C 108 °C T 161 °C 160 °C

– The capacitance and inductance of the connecting

cable has to be considered.

– The O

2

Oxygen sensor type InPro 6XXX can be

used in / with the fittings InFit®76*-*** or InTrac

®

7**-***, or in / with other suitable fittings in potentially explosive areas.

– The metal body of the O

2

Oxygen sensors, or the fittings InFit 76*-*** or InTrac 7**-***, or other appropriate fitting is optionally included in the routine pressure test of the system.

– The independent fitting used for installation of O

2

Oxygen sensor must be conductively connected to the equipotential bonding system.

InPro 6950 Series O2Sensor 12 mm 11

2.7 Ex-classification FM approved

A

B

C

D

E

F

E

D

C

B

A

1 2 3 4 5 6 7 8

Index

Title

Drawing No

METTLER TOLEDO

Process Analytics

CH-8902 Urdorf

Drawn F.Kogelmann 11-Dez-03 Scale 1:1

Change Dario Meier 25-Mai-16 Format DIN A3

Schutzvermerk ISO 16016 beachten / Refer to protection notice ISO 16016

Note - Replaces -

FM control drawing

53800002

E.4

Model: MODEL NAME

E.4

ArtikelNr: 53800002

Drawing: E.4 Rel.Level: Released Sheet: 1

/

1

R

Notes:

1. No revision to this drawing is permitted without FMRC approval.

2. Vmax > Vt; Imax > It; (Ci of all loops + C cable) < Ca; (Li of all loops + L cable) < La

Pmax or Pi > Po

3. Single Multi-Channel IS Barrier or Apparatus must be FMRC Approved.

4. Single Multi-Channel IS Barrier or Apparatus manufacturer`s control drawings

must be followed when installing the System. IS Barrier or Equipment may be

installed within the Hazardous (Classified) location for which it is approved.

5. Installation must be in accordance with Article 500 of the NEC (ANSI/NFPA 70) and

ANSI/ISA RP12.6.

WARNING: substitution of components may inpair intrinsic safety.

Entity Parameters:

Vmax (Ui)=16V, Imax (Ii)=50mA, Pi=0.25W

Ci=0.1 uF, Li=0 mH

Probe

Class I, Division 1, Groups A, B, C and D

Class II, Division 1, Groups E, F, and G

Class III, Division 1

T6 Ta=60 C

HAZARDOUS (CLASSIFIED) LOCATION

Any FMRC Approved Single

Multi-Channel Barrier or Apparatus

NONHAZARDOUS LOCATION

12 InPro 6950 Series O2Sensor 12 mm

InPro 6950 © 02 /17 Mettler-Toledo GmbH 52 206 137 Printed in Switzerland

3 Product description

3.1 General information

The oxygen sensor InPro 6950 with integrated temperature probe is used for meas ure ment of oxygen at low concentrations.

The sensor is sterilizable and compatible with CIP (cleaning in place).

InPro 6950 sensors with ISM

®

functionality offer Plug and Measure as well as enhanced diagnostics features.

3.2 Principle

The InPro 6950 is a Clark polarographic O2sensor that has been expanded with a separate reference and guard ring electrode. This 4-electrode system is characterized as follows:

a) The measurement system of this InPro 6950

sensor consists of a working electrode (cathode), a counter electrode (anode), a reference electrode and a guard ring electrode. The measurement system is separated from the process medium by an oxygen permeable membrane.

b) The transmitter supplies a constant voltage to

the cathode and the guard ring electrode so that oxygen can be reduced on both electrodes.

c) The oxygen molecules migrate from the measure-

ment medium through the membrane to the cathode to which the voltage is supplied and are reduced. At the same time, oxidation takes place at the anode and oxygen and water are released into the electrolyte. This causes a current to flow between the anode and cathode which is directly proportional to the partial pressure of oxygen (pO

2

) in the process medium.

d) The guard ring electrode built into the sensor

reduces the oxygen that migrates to the side of the cathode and can distort the measurement. The guard ring electrode therefore enables traces of oxygen to be precisely determined at even the lowest concentrations.

InPro 6950 Series O2Sensor 12 mm 13

The 4-electrode system of the InPro 6950 guarantees a high degree of precision, rapid response and a low detection limit.

Please refer to “Section 10–Theory of the polarographic sensor” for further information.

3.3 Scope of delivery

Each InPro 6950 sensor is supplied fully assembled and factory-tested for correct function together with:

– a quality control certificate – inspection certificates 3.1

(complying with EN 10204)

METTLER TOLEDO DO sensors are supplied with fitted membrane body filled with electrolyte and covered with the watering cap and have been checked for proper function.

See electrolyte order details at section „Spare Parts“,

9.3.

Cathode (Pt)

4-electrode Measurement Technology

Guard (Pt)

Reference (Ag/AgCl)

Anode (Pt)

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3.4 Equipment features

12 mm sensor

Washer

Anode (Pt) Cathode and Guard Ring

Watering Cap

Cap Sleeve (N-type)

O-ring (silicone FDA/USP VI)

Membrane Body InPro 6950 (gas)

Retainer Nut

Reference (Ag/AgCl)

Interior Body

O-ring (10.77 3 2.62 mm, silicone FDA)

O-ring (9.0 3 1.0 mm, silicone FDA/USP VI)

Pg 13.5 Threaded Sleeve

VP Connector (straight version)

InPro 6950 Series O2Sensor 12 mm 15

4 Installation

4.1 Mounting the sensor

Important! Remove the watering cap before

mount ing the sensor.

Mounting the sensor in a housing

Please refer to the instruction manual of your housing explaining on how to mount the sensor in place.

Mounting the sensor directly on a pipe or a vessel

The 12 mm sensors can be mounted directly through a socket with inside thread Pg 13.5 and securely tightened via the Pg 13.5 threaded sleeve.

4.2 Connection

4.2.1 Connecting the InPro 6950 to a VP cable

The sensor is connected to the transmitter via a VP cable. The VP cable ensures a secure connection between the transmitter and the sensor under harsh industrial conditions. The robust watertight IP68 connector housing guarantees maximum process safety.

Do not touch the sensor at the VP connector plug!

To connect the VP cable to the sensor align the slit of the VP connector with the pin in the plug. Then tightly screw the plug to fasten the two parts.

Admissible mounting position

Zulässige Einbaulage

Positionement de montage admis

Inadmissible angle

Unzulässiger Winkel

Angle non admissible

52910094ME

15° 15°

16 InPro 6950 Series O2Sensor 12 mm

InPro 6950 © 02 /17 Mettler-Toledo GmbH 52 206 137 Printed in Switzerland

4.2.2 Connecting the VP cable to the transmitter

Note: Cable assignment can be found in the

METTLER TOLEDO VP cable instruction manual.

Note: For connecting the cable to the terminals of the transmitter, please refer to the instructions given in the METTLER TOLEDO transmitter manual.

VP-Connector

Slit

Plug

VP-6 Cable for Standard Use

O2 Transmitter

VP Cable

InPro 6950 Series O2Sensor 12 mm 17

5 Operation

Important! Before using the sensors for the first time,

the electrolyte should be replaced (see “Chapter

6.2”). Due to possible adverse conditions during transport and storage (e.g. airfreight; pressure and temperature variations), the quality of the electrolyte may become impaired. Poor electrolyte quality can lead to erroneous measurement values.

5.1 Start-up and polarizing

Important! The watering cap must be removed before

mounting the sensor in the process.

When the system is operated for the first time or if the sensor has been disconnected from the voltage source (transmitter or O

2

sensor master) for longer than 5 min utes, the sensor has to be polarized prior to calibration by connecting it to the operating O

2

transmitter or to a sensor master. After 6 hours, the sensor is fully polarized and ready for operation. During this time, it is recommended to keep the watering cap filled with conditioning solution on the sensor (see “Section 7– Storage”), especially if the sensor is being polarized for longer than 6 hours.

A shorter polarization period is sufficient if the sensor has been disconnected for only a few minutes. The following table serves to establish the correct polarization time in relation to the depolarization time.

Important! Setting of the polarization voltage on the transmitter for correct measurements:

– Standard applications: –675 mV

Depolarization time1 Minimum required t

depol

[Min.] polarization time

2

[Min.]

t

depol

> 30 360

30 > t

depol

> 15 6 3 t

depol

15 > t

depol

> 5 4 3 t

depol

t

depol

< 5 2 3 t

depol

1 Depolarization time: Time span in which the pola- rization voltage is cut off from the sensor. This is the case during: – change of electrolyte – change of membrane body – the time the cable is disconnected or no transmitter or sensor master is connected to the cable. 2 Polarization time: Time span during which the sensor is under a polarization voltage.

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– Measurement of permanently low oxygen concen-

trations (<500 ppb in liquids or <10,000 ppm [vol.] in gases) in the presence of volatile acidic components (e.g. carbon dioxide during measurements in breweries): –500 mV

Note: To ensure the supply of the correct polari za tion voltage the transmitter must be set accordingly.

5.2 Calibration

5.2.1 Purpose of calibration

Each oxygen sensor has its own individual slope and own individual zero point. Both values are subject to change, for example, through electrolyte consumption or after exchange of electrolyte or membrane body. To ensure high measurement accuracy of the sensor, a calibration must be carried out after each change of electrolyte or membrane. Prior to calibration, the sensor has to be polarized for at least 6 hours.

Please remove the watering cap from the sensor, rinse the sensor with water and dry it for at least 10 minutes before starting calibration.

To check if your sensor needs a recalibration, you may dry it and take it in the air to check that the reading is close to 100%. If not, then the sensor needs a new calibration.

5.2.2 What you have to know for calibration

Calibration is generally carried out at the polarization voltage at which measurements are taken.

Zero-point calibration is recommended: – when measuring less than 5 ppb in liquids – when measuring less than 125 ppm (by vol.) in

gases

The automatic calibration routine in the M 700 transmitter (SW700-011 “CO

2

compensation”) is

not suitable for the InPro 6950 sensor.

General remarks: – For calibration in air, the sensor membrane

must be dry, since adhering water drops can

falsify the measured oxygen value.

– Make sure that the oxygen saturation index of

the calibration medium is correct and remains constant during calibration.

– In the event of calibration in water or sample

medium, the calibration medium must be in equilibrium with the air. Oxygen exchange between water and air is only very slow. Therefore it takes quite long time until water is saturated with atmospheric oxygen.

InPro 6950 Series O2Sensor 12 mm 19

– For correct calibration, a minimum flow rate of the

calibration medium is necessary.

– Make sure that all other parameters, such as

temperature and pressure, are constant.

For continuous applications, we recommend period-

ic recalibration in line with your requirements on accuracy, the type of process in operation and your own experience. The frequency of the need for

re- calibration depends very much on the specific application, and therefore appropriate intervals cannot be exactly defined here.

5.2.3 Single point calibration

By carrying out a single point calibration, the factual slope of the sensor can be established. The calibration medium can be water with known oxygen saturation index (e.g. air-saturated water) or air with known water-vapor saturation (e.g. water-vapor saturated air).

After the sensor signal has stabilized, the complete meas uring system can then be calibrated to the100% value of the desired measurable variable, e.g.100% air, 20.95 % O

2

, or 8.26 ppm at 25°C (77°F) and normal pressure (see instruction manual for the transmitter).

5.2.4 Dual point calibration

By carrying out a dual point calibration both slope and zero point of the sensor can be established.

Important! In case of a dual point calibration, always start by the zero point calibration before

calibrating the slope.

As a rule, the zero point should be adjusted to zero manually, or it is automatically performed by the transmitter (see instruction manual for the transmitter).

Zero-point calibration is recommended: – when measuring less than 5 ppb in liquids – when measuring less than 125 ppm (by vol.) in

gases

Attention! Incorrect zero point calibration is a frequent source of measurement error. For correct calibration, we recommend the use of carbon dioxide gas with a level of purity of at least

99.9995 %.

After the sensor signal has stabilized (after 6… 12 hours), the sensor can be calibrated through the relevant transmitter to the 100% value of the desired measurable variable, e.g. 0% air, 0.0% O

2

, or

0.0ppm (see instruction manual for the transmitter).

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6 Maintenance

6.1 Inspection of the sensor

6.1.1 Visual inspection

To check your sensor, we recommend the following procedure:

– The contacts of the connector must be dry.

Moisture, corrosion and dirt in the connector can lead to false readings.

– Check the cable for buckling, brittle areas or

ruptures.

– Before calibration always examine the membrane

foil optically for signs of damage. The foil must be intact and clean. Dirty membranes should be wip ed clean using a soft, moist tissue.

Note: An undulated membrane has no influence

on the sensor performance, assuming the membrane is intact.

– The membrane body must be replaced if the

sensor has too long a response time, the reading is unstable or subject to drift, and if the sensor cannot be calibrated or the membrane shows sign of mechanical damage.

– Check the cathode area for discoloration, conta -

mination or cracks in the glass. If necessary rinse with demineralized water and clean with a clean soft brush or soft paper tissue.

Attention! Do not use any cleaning agents contai ning alcohol. This could damage the sensor or lead to fault current.

Attention! The glass body is fragile and sensitive to vibration.

InPro 6950 Series O2Sensor 12 mm 21

6.1.2 Testing the METTLER TOLEDO O2sensor master InPro 6950

We recommend to use the METTLER TOLEDO O

2

sensor master InPro 6950 to check the quality

of your sensor as follows:

• Connect the sensor to the O

2

sensor master.

As soon as the sensor is connected to the O

2

sensor master, the polarization function is automatically activated. Please note: if the sensor was disconnected from the transmitter for longer than 5 minutes, the sensor must be polarized first (pola rizing time see “Section 5.1”) to get representative test results.

• Battery Check:

Push the switch to the left. If the battery is ok and

the O

2

sensor master is operational the green LED lights up. Otherwise, please consult the instruction manual of the O2sensor master.

• Sensor Check:

For this test the O

2

sensor must be fully polarized

and the membrane of the sensor must be dry

and clean.

Expose the sensor (connected to O

2

sensor master) to the air. By pushing the switch to the right to the position “2– Sensor check”, the O2sensor master checks wether the electrode current for air measurement delivered by the sensor is within the admissible range (2500 to 6000 nA for InPro 6950).

METTLER TOLEDO

O

2

Sensor-Master

InPro 6900

Order No. 52 200 893

The polarization function

will be activated automatically

,

when a sensor is connected.

After the sensor polarization

you should check the functions

of the sensor as following:

1. Battery Check

2. Sensor Check

Green light = ok

left

Battery Check

middle

Autom. Polariz.

right

Sensor Check

1

2

Switch

LED

22 InPro 6950 Series O2Sensor 12 mm

If the green LED lights up the current for air

measurement is with in the admissible range.

If the LED does not light up, you should check the

battery of the O

2

sensor master (see instruction manual “Accessories”). If the battery is working, than there is probably a problem with your sensor. You should change the electrolyte and/or the membrane body of your sensor. If after a membrane change the LED still does not light up, this means that there is maybe something wrong with the interior body of the sensor. You should then change it (see “Section 6.2”).

Important! The Sensor Check function only verifies

the correctness of the electrode current for air measurement. In order to be absolutely sure of the functionality of the sensor, the residual signal in an oxygen free medium should also be controlled (see “Section 6.1.3”).

Important! The InPro 6950 sensor is not compati-

ble with the O

2

sensor master of the InPro 6900 or

any other conventional polarization unit.

The 4-electrode system of the InPro 6950 sensor

can only be checked and/or polarized directly on the transmitter or with the InPro 6950 O2sensor master.

6.1.3 Testing the sensor via a transmitter

A periodic zero current measurement (no zero point calibration!) is recommended for verification of prop-

er sensor function.

Note: At the time you carry out the zero current measurement, the sensor must be polarized.

Zero current measurement can be done by using zero ing gel (order no. 30 300 435) or nitrogen (N

2

) or carbon dioxide (CO2) calibration gases with a purity of at least 99.995%, alternatively in a sample medium saturated with one of these gases.

After 2 minutes in an oxygen-free sample medium, the reading on the transmitter should drop to below 10% of the reading in ambient air, and within 10 minutes the value should have dropped to below 1%.

If the measured values are too high, this suggests a depleted electrolyte or a defective membrane. In the first instance replace the electrolyte, and in the second case exchange both the membrane body and the electrolyte accordingly.

If after such procedures the above mentioned values are still not reached, replace the interior body. If this doesn’t solve the problem too send the sensor to your local METTLER TOLEDO representative for inspection.

InPro 6950 Series O2Sensor 12 mm 23

Many sample media contain volatile substances which, even at very low concentrations, have a clearly perceptible smell. Similarly to oxygen, these substances are able to invade the electrolyte through the gas-permeable membrane. Accordingly, they become noticeable when changing the electrolyte. In most cases, such substances have absolutely no influence on the measuring properties of the sensor. Slight discoloration of the electrolyte also has no effect on the measuring properties.

6.2 Changing the electrolyte, the membrane body or the interior body

Note: The InPro 6950 uses a special electrolyte

which contains an oxygen scavenger. This electrolyte ensures fast response time and together with the guard ring increases the signal stability of the sensor. The electrolyte must be exchanged on a regular basis or when the sensor has been exposed to the air for more than 24 hours without a watering cap or if the sensor has been stored for several months.

Note: The content of the electrolyte bottle has to be used within 3 months after opening.

If the membrane and/or the interior body exhibits signs of failure (long response time, increased current in an oxygen-free medium, mechanical damage, etc.) the membrane body and/or the interior body has to be replaced.

Warning! The O

2

electrolyte has an alkaline pH value. Contact of electrolyte with mucous membrane or eyes is to be avoided. Therefore protective gloves and

safety glasses have to be worn for the following dismantling works.

If such contact occurs, the affected area should be well rinsed with water. In the case of accident, or should ever any adverse signs appear, get immediate medical attention.

When changing the electrolyte, the membrane body or the interior body, please observe the following instructions (see also the following illustration):

Attention! Make sure that this maintenance step is carried out in clean place.

1. Unscrew the cap sleeve from the sensor shaft

and carefully pull it off the sensor.

2. Pull off the membrane body from the interior

body. If it is tight-fitted, eject by pushing it with the flat finger tip. Before electrolyte is refilled, the membrane body must be removed from the cap sleeve!

24 InPro 6950 Series O2Sensor 12 mm

3. Rinse the interior body with demineralized water

and carefully dab it dry with a paper tissue.

Note: steps 4 to 7 may only be carried out

when changing the interior body.

4. Unscrew the retainer nut of the interior body with

an adjustable wrench or with a 3/8" wrench.

5. Remove the interior body by pulling it out of the

sensor shaft. If necessary use a plier.

Warning! Do not twist the interior body. Other -

wise the connection pins can be damaged.

6. Insert the new interior body in the sensor shaft.

Turn the interior body in the shaft until the slit of the interior body is aligned with the pin placed in the shaft.

7. Press the body in the shaft and screw the new

retainer nut in place.

8. Examine the O-rings visually for mechanical

defects, and replace if necessary.

9. Half-fill the new membrane body with O

2

electrolyte.

Note: The electrolyte bottle is equipped with a

special pouring system. To ensure proper functioning, hold the bottle vertically, upsidedown.

Note: make sure that all air bubbles are removed

from the membrane body. Air bubbles can be removed by carefully tapping on the membrane body.

10. Slip the membrane body over the interior body

while holding the sensor in a vertical position. The excess electrolyte will be displaced and have to be removed with a paper tissue.

Important! No electrolyte, sample media or

contamination may be present between the membrane body and the cap sleeve. Please check carefully!

1

⁄

2

1

⁄

2

O2 Electrolyte

InPro 6950 Series O2Sensor 12 mm 25

11. Carefully slip the cap sleeve over the fitted

membrane body, holding the sensor in a vertical position and screw it tight. The cap sleeve must be clean and dry.

12. After each exchange of electrolyte or membrane

body, the sensor has to be repolarized and re calibrated.

26 InPro 6950 Series O2Sensor 12 mm

Replacement of the interior body

3/8"

O-ring (silicone FDA/USP VI)

Cap Sleeve (N type)

Membrane Body

Retainer Nut

Interior Body

Slit O-rings

O-ring (9.0 3 1.0 mm, silicone FDA/USP VI)

O-ring (10.77 3 2.62 mm, silicone FDA)

InPro 6950 Series O2Sensor 12 mm 27

7 Storage

For storage periods longer than 24 hours, we re commend you to use a watering cap filled with the same cleaning and conditioning solution as that used for our portable DO measurement system (order no. 52 200 255). This solution contains an oxygen scavenger which ensures that the electrolyte of the sensor does not come into contact with oxygen when not in use.

Prepare the cleaning and conditioning solution as follows: Dissolve one tablet in 40 ml of deionized water and wait 5 minutes for the tablet to be completely dissolved. Fill the watering cap with this solution and place it over the tip of the sensor. This solution has some cleaning properties which will keep the membrane free of microorganisms. In case you do not have any cleaning and conditioning set, you may also use checking gel or deaerated water in the watering cap. Before mounting the sensor in the process, always remove the watering cap and rinse the tip of the sensor with water.

Attention! The electrolyte should be replaced before use if the storage period exceeds 3 months.

Attention! If the storage period exceeds 6 months,

the sensor should be stored dry, i.e. without any electrolyte in the membrane body. A sensor being stored dry (without electrolyte in the membrane body) may on no account be connected to the O

2

sensor master InPro 6950 or any other polarization module.

28 InPro 6950 Series O2Sensor 12 mm

8 Product specification

8.1 Certificates

Each sensor is delivered with a set of 3.1 certificates (complying with EN 10204).

All wetted metal parts (sensor shaft, cap sleeve and membrane body) are identified with a engraved symbol corresponding to the heat number on the paper certificate delivered with the sensor.

Each wetted metal part (sensor shaft, cap sleeve and membrane body) is polished in order to get a surface roughness lower than 0.4 µm (16 µin). This represents a roughness grade number of N5 (according to ISO 1320:1992).

InPro 6950 Series O2Sensor 12 mm 29

8.2 Specifications

InPro 6950

Measurement principle Amperometric/Polarographic Working conditions

Pressure resistance measurement 0.2 … 6 bar absolute

[2.9… 87.0 psi absolute] gas applications

0.2… 9 bar absolute [2.9… 130 psi absolute] liquid applications

Mechanical pressure resistance Max. 12 bar absolute

[174.0 psi absolute]

Measuring temperature range 0 …70 °C [32… 158°F]

gas applications 0… 80 °C [32… 176°F] liquid applications

Temperature range (mechanical) – 5 … 121°C [23 …250 °F]

(sterilizable)

Construction

Temperature compensation Automatic with built-in RTD Cable connection VarioPin (IP 68),

straight or angled

O-ring material Silicone FDA and

USP VI approved Membrane material PTFE/Silicone Wetted metal parts (3.1) Stainless steel

Special material on request Surface roughness of N5 (Ra < 0.4 µm [16 µin]) wetted metal parts (ISO 1320:1992) Quick disconnect interior body Traces Cathode Pt Anode Pt Guard ring Yes (Pt) Reference Ag/AgCl

Dimensions

Sensor diameter 12 mm [0.47"] Immersion length (a) for 12 mm sensor 70, 120, 220, 320 mm

[2.8, 4.7, 8.66, 12.6"]

Performances

Detection limit 0.1 ppb (water)

0.25 ppb (water/ CO2) 5 ppm (vol.) gas

Accuracy ± [1 % + ± 0.1 ppb] of reading

in liquids

± [1% + ± 0.25ppb] of reading

in CO2 containing liquids

± [1 % + ± 5 ppm] of reading

in gas Response time at 25°C/77 °F (air →N2) 98% of final value < 90 s Sensor signal in ambient air (25°C/77 °F) 2500 …6000 nA Residual signal in oxygen-free medium < 0.025%

of the signal in ambient air

Certification

EHEDG, 3A Yes (pending)

3.1 (EN 10204) Yes ATEX Certificate Yes FM Approval Yes FDA/ USP VI Yes Quality Control Yes

Compatibility

with METTLER TOLEDO transmitters see “Section 9.4” with METTLER TOLEDO housings see “Section 9.5”

30 InPro 6950 Series O2Sensor 12 mm

9 Ordering information

For more detailed information refer to the technical data sheet. Ask your local distributor.

9.1 Sensors

9.2 Accessories

9.3 Spare parts

Sensor Order No.

InPro 6950/12/070/VP (2.8") 52 206 097 InPro 6950/12/120/VP (4.7") 52 206 098 InPro 6950/12/220/VP (8.7") 52 206 099 InPro 6950/12/320/VP (12.6") 52 206 100 InPro 6950/12/070/VP90 (2.8") 52 206 101 InPro 6950/12/120/VP90 (4.7") 52 206 102 InPro 6950/12/220/VP90 (8.7") 52 206 103 InPro 6950/12/320/VP (12.6") 52 206 104 InPro 6950/12/060 (2.4") V80 52 206 110

Accessory Order No.

O2 sensor master InPro 6950 52 206 113 O2 sensor simulator 52 200 891 Cap sleeve with protective cage (P type)* 52 200 038 Cap sleeve w/o protective cage (N type)* 52 200 037 VP cable VP6-ST/3 m 52 300 108 VP cable VP6-ST/5 m 52 300 109 VP cable VP6-HT/3 m 52 300 112 VP cable VP6-HT/5 m 52 300 113 VP cable VP8-ST/3 m 52 300 354 VP cable VP8-ST/5 m 52 300 355 VP cable VP8-HT/3 m 52 300 361 VP cable VP8-HT/5 m 52 300 362 Oxygen zeroing gel (3 × 25 ml) 30 300 435

* 1.4404

For other cable lengths or types, please contact your local METTLER TOLEDO representative.

Spare part Order No.

Membrane body, single, InPro 6950 52 206 105 Membrane kit InPro 6950 52 206 106 (4 membrane bodies, 1 O-ring set, 235 ml electrolyte bottle, watering cap) Membrane body, single, InPro 6950 Gas 52 206 108 Membrane kit InPro 6950 Gas 52 206 109 (4 membrane bodies, 1 O-ring set, 235 ml electrolyte bottle, watering cap) InPro 6950 electrolyte pack (335 ml) 30 298 426 Interior body InPro 6950 52 206 112 (with quick disconnect)

Mettler Toledo InPro 6950 Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual