Calibration Of The Sensor And Ph Transmitter - Mettler Toledo InPro 3100 Serie Instrucciones Generales

General instructions for the pH combination electrode type InPro
1. Introduction
The METTLER TOLEDO pH sensor type InPro 3100 is a low-maintenance, autoclavable and pressure-resistant measuring electrode with a gel-type
reference electrolyte. The reference element incorporates a silver-ion trap to prevent silver sulfide precipitation on the diaphragm. In case of
InPro 3100, a temperature sensor is integrated, mainly for automatic temperature compensation possibilities of the pH signal during calibration
and operation. Please read these instructions carefully before putting the sensor into operation, in order to ensure faultless operation.
The InPro 3100 sensor is mainly designed for the measurement of pH value in biotechnical processes at moderate pressures (< 6 bar). It can be
used under industrial fermentation, pilot and laboratory conditions, and is particularly intended for those processes where intermediate steriliza-
tion or autoclaving is indispensable.
2. Safety remarks
The sensor is intended only for the use described in point1 above. The sensor consist partly of glass. If a sensor is to be cleaned or calibrated
using acid or alkaline solutions, safety goggles and gloves should be worn. Please follow the guidelines enclosed for an installation in the Ex-
zone.
3. Product description
The markings on the glass shaft of each sensor include the following information:
®
InPro
31XX / *
Pt100 / Pt1000
combination pH
pH 0 ... 14
0...80 °C / 140 °C (130 °C)
Order No. 52 00X XXX
II 1/2G EEx ia IIC T6/T5/T4
SNCH 00 ATEX 3130 X
IS CLI, Div1, GR ABCD
Follow the operating instructions
Additionally, the sensor is supplied with a serial number on the connector cap for identification possibilities for each sensor produced.
4. Installation and preparation for use
1. On unpacking, check the sensor for mechanical damage of the pH sensitive glass and shaft. Report any damage immediately to your
METTLER TOLEDO supplier.
2. Remove the watering cap and briefly rinse the sensor with de-ionized water. After rinsing, the sensor should only be dabbed dry with a tis-
sue. Do not rub the pH-sensitive glass, since this can lead to electrostatic charging and sluggish response times.
3. Check the space behind the pH-sensitive glass for the presence of any air bubbles and remove same by gently swinging the sensor in a ver-
tical plane.
4. Please refer to the instruction manual of the relative housing in order to install the sensor.
5. Connect the sensor to the pH transmitter, using a cable with the appropriate connector (VP connector for InPro 3100). Please refer to the
wiring and terminal diagram accompanying the cable.
5. Operation

5.1 Calibration of the sensor and pH transmitter

For the InPro 3100 sensor a 2-point pH-calibration is recommended. Before calibration, first remove the watering cap. To speed up the response
time of the sensor after long transport and storage periods, and before calibration, dip the sensor into buffer pH 7, buffer pH 4 and buffer pH 7
again, each time for about one minute. The sensor is then dipped successively into two different buffer solutions with given pH reference values
and the transmitter calibrated to these buffer values. Normally you start with buffer pH 7 for determining the 0-point and then buffer pH 4 or 9 for
determining the slope. In the case of microprocessor-based transmitters with buffer recognition, the order of the two chosen buffer solutions is ir-
relevant. Whenever possible, a temperature sensor (for InPro 3100 the integrated one) should be connected to the transmitter and «automatic tem-
perature measurement» selected there. Please refer to the instruction manual of the transmitter for further details.
5.2 Sterilization of the sensor
The InPro 3100 sensor can be sterilized either through autoclaving (remove red protection cap) or through in-situ sterilization with steam or su-
perheated fermentation medium. Sterilization temperatures above 140 °C are not allowed, and excessive sterilization time (for instance t >> 30
min at 140 °C) could notably shorten the life time of the sensor. Repeated sterilization and/or autoclaving of the sensor can lead to a slight col-
oration of the electrolyte. This color change does not effect the functioning of the sensor.
5.3 Temperature sensor of InPro 3100
As mentioned above, the Pt 100/1000 sensor integrated into the InPro 3100 is primarily intended for automatic temperature compensation of the
pH-signal and not for any accurate and safe temperature indication or control of the process temperature. If you anyhow want to try this, check
that your transmitter has the required temperature indication accuracy and a free outlet for the signal. Furthermore, a calibration of the tempera-
ture signal might be necessary.
6. Maintenance
1. Carefully rinse the sensor tip and diaphragm with de-ionized water after each production cycle. Under no circumstances must measuring solu-
tion be allowed to dry on these parts!
2. When the sensor is not in operation, store it with sensor tip and diaphragm well submerged into 9823/3M KCl or 9816/Viscolyt electrolyte.
3. If the sensor is stored mounted in its housing, the same rule as in 2) above applies, but the storage electrolyte has to be slightly modified,
with 2 parts of buffer solution pH 9.2 to 10 parts of electrolyte, this in order to avoid corrosion of housing parts.
4. If a sensor is stored dry for a few days by mistake, let it soak in the normal storage electrolyte for several hours before use.
5. Occasionally check the connector for possible traces of moisture. If necessary, clean well with de-ionized water or alcohol, and afterwards
dry carefully.
7. Trouble-shooting (sluggish response time, insufficient sensitivity etc.)
The glass membrane can be reactivated using a HF solution (order no. 51 319 053). The sensor tip (only pH sensitive glass part) is immersed
into the HF solution for a period of about 5 minutes, is then immediately and thoroughly rinsed with de-ionized water and thereafter stored in buffer
solution pH 4 (see point 6 above) up to the diaphragm for 12 hours.
Possible protein precipitation and blockage of the diaphragm can be treated with our special sensor cleaner (order no. 51 340 068). However,
use of the diaphragm cleaner (order no. 51 340 070) is normally not necessary for this sensor type, as the built-in silver-ion trap prevents the
formation of silver sulfide contamination.
Also, check the connector for possible traces of moisture. If necessary, clean well using de-ionized water or alcohol, and afterwards dry carefully.
8. Disposal
If no relative official regulations are in force, used or defective InPro 3100 sensors and the packaging can be disposed of as ordinary household
waste.
9. Warranty
In the event of manufacturing faults, 12 months warranty from date of production is granted.
designation / shaft length in mm
type of built-in temperature sensor
type of sensor
pH measurement range
temperature range for operation / sterilization (for InPro 3100UD)
article number for ordering
Ex-classification
designation and number of certificate
FM approved
note
®
3100