Mettler Toledo InPro 4250 Instrucciones Generales página 3

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General instructions for pH combination electrode types InPro

Introduction

These general instructions must be readily available to operators of the electrode at all times. Before using the electrode, these instructions must be read and

understood by all operating personnel. METTLER TOLEDO pH sensors type InPro 4250 and InPro 4250 SG (ISM) are low-maintenance, pressure-resistant

measuring electrodes with a polymer electrolyte XEROLYT

for the simultaneous measurement of pH value and temperature in industrial processes.

The sensor InPro 4250 / InPro 4250 SG (ISM) is suitable for applications involving:

• heavily contaminated media

• emulsions and suspensions

• solutions containing protein

• acid solutions

InPro 4250 / InPro 4250 SG sensors are non-sterilizable /non-autoclavable and unsuitable for measurements, in media containing chlorine or bromine.

Safety remarks

The sensor is intended only for the use described in §1 above. The sensor consists partly of glass. If the sensor is to be cleaned or calibrated using acid or

alkaline solutions, safety goggles and gloves should be worn. In addition, local and in-house-safety regulations must be observed. We recommend that the

electrodes only be put into operation in conjunction with original products/accessories from METTLER TOLEDO. The electrodes may be operated and serviced

only by personnel familiar with the equipment in question and who have read and understood these instructions. Please follow the guidelines enclosed for an

installation in the hazardous areas.

The electrodes are designed to withstand a maximum operational pressure of 8 bar and fulfill all current PED requirements (Pressure Equipment Directive

97/23/EC, Art. 3, Sec. 3.). Please take extra care during installation/fitting of the sensor to ensure that neither the polymer body/shaft of the sensor nor the

thread (Pg 13.5) suffer any injury or damage. Please do not touch or hold the electrode directly at the plug. Electrostatic discharge can damage the chip.

Product description

The markings on each sensor provide the following information:

InPro

425X (SG) / XXX / YYY / ZZZ designation (Solution Ground Option) / shaft length in mm / temperature sensor / ISM (option)

combination pH

Pt100 / Pt1000

pH 0 ...14 / pH 1 ...14

0 ...130 °C

II 1/2G EEx ia IIC T6/T5/T4/T3 Ex classification

SNCH 00 ATEX 3130 X

IS/I, II, III/1/ABCDEFG/T6

Follow the operating instructions note

Order No. 52 002 14X

Additionally, the sensor is supplied with a serial number on the connector cap for identification purposes for each sensor produced.

Installation and preparation for use

On unpacking, check the sensor for mechanical damage of the pH-sensitive glass and shaft. Report any damage immediately to your METTLER TOLEDO

supplier.

Remove the watering cap and rinse the sensor with de-ionized water. After rinsing, the sensor should only be dabbed dry with a tissue. Do not rub the

glass membrane, since this can lead to electrostatic charging and sluggish response times.

Check the membrane chamber of the glass electrode for the presence of any air bubbles and remove same by lightly swinging the sensor in a vertical

plane.

Please refer to the instruction manual of the relative housing in order to install the sensor.

Connect the sensor to the pH transmitter, using a cable with the appropriate connector. Please refer to the wiring and terminal diagram accompanying

the cable.

For InPro 4250 SG electrodes, with an additional Pt auxiliary electrode, connect the corresponding blue wire in the VP cable to your transmitter in

accordance with instructions in the connection diagram of VP cable and/or in the transmitter instruction manual. For ORP measurement (sep. transmitter

needed) connect solution ground (blue wire) with ORP input.

InPro 4250 SG electrodes with ISM allow "Plug and Measure" as well as advanced diagnostics. Operation of the electrodes in ISM mode requires the

use of a special VP8 cable as well as an ISM pH-module for the transmitter M 700 (software). For installation, startup and operation of the ISM system

please refer to the relative instructions provided with the cable and the module.

Calibration and measurement

InPro 4250 sensors require 2-point calibration. To calibrate, first remove the watering cap. The sensor is then dipped in succession into two different buffer

solutions with given pH reference values and the transmitter calibrated to these buffer values (for example buffer pH 4.01 an d pH 7.00). Please refer to the

instruction manual of the transmitter for details.

Maintenance

The sensor with polymer electrolyte XEROLYT

to recondition it before use by immersion in Friscolyt™ (Order no. 51 340 053) for at least 24 hours. After each working cycle, the sensor tip and the aper-

tures (diaphragms) must be thoroughly cleaned using de-ionized water.

Trouble-shooting

Sluggish response time.

The glass membrane can be reactivated using a HF solution (order no. 51 319 053). Only that section of the sensor tip below the two (diaphragms)

apertures may be immersed in the HF solution, and this during a period of about 5 minutes. Immediately afterwards, rinse the sensor thoroughly and

immerse in Friscolyt™ for at least 12 hours.

Insufficient sensitivity (slope).

Check the apertures for contamination and rinse with warm water. Check the VP connector for traces of moisture. If necessary, clean well using de-

ionized water or alcohol, and afterwards dry carefully.

Disposal

If no relative official regulations are in force, used or defective InPro 4250 / InPro 4250 SG sensors and the packaging can be disposed of as ordinary house-

hold waste.

Warranty

In the event of manufacturing faults, 12 months warranty from date of production is granted.

PLUS and a built-in temperature sensor. InPro 4250 / InPro 4250 SG (ISM) sensors are designed

• sulfide-bearing media

• hot alkaline (caustic) solutions

• processes with wide pressure fluctuations

• solvents

type of sensor

type of built-in temperature sensor

pH measuring range InPro 4250 / InPro 4251 and InPro 4252 (SG) (with reduced performance

and lifetime at pH 12 ... 14)