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WTW Multi-parameter Measurements

pH, Dissolved Oxygen and Conductivity Measurements – Multi-parameter Instruments


  1. Laboratory Multi-parameter Instruments
  2. Portable Multi-parameter Instruments
  3. Multi-parameter Sondes

Convenient and cost efficient of up to 5 parameters simultaneously: This is modern multi-parameter measurement by WTW. The meters have all functionalities for pH, ORP, dissolved oxygen, conductivity, salinity and Temperature measurement, and for an MPP IDS additionally depth measurement.


Multi-parameter measurements are very common in the field, typical applications are ground water pumping tests, profile measurements, monitoring of surface water and many more. The most modern variant is the MultiLine® IDS systems which allow measurements up to 5 parameters with intelligent digital parameters up to 100 m water depth.


For the laboratory WTW offers the new inoLab® Multi IDS meters with one, two or three universal measuring channels. The most interesting feature is the efficient automatic sampling of GLP compliant data, e.g. for quality assurance laboratories.


inoLab® Laboratory Multi-parameter Instruments


Sets for benchtop meters

All benchtop meters are available in application oriented sets including sensors and accessories.



… with the state-of-the-art multi-channel instruments inoLab® Multi 9430 IDS and inoLab® Multi 9420 IDS


inoLab? Multi 9420 IDS & inoLab? Multi 9430 IDS


  • Measuring safety without compromises
  • Digital sensor recognition
  • Antibacterial keypad


WTW digitale IDS-Sensoren


Cutting edge technology from WTW for demanding laboratory applications. Two digital inoLab® multi-parameter instruments for IDS sensors for parallel measuring of one identical or varying parameters. Up to three sensors (inoLab® Multi 9430 IDS) can be connected. A large glass shield protects the graphic display and supports the presentation of the measuring values and recognition of important information. The innovative and antibacterial keypad helps to protect against microbiological contamination. The solid zinc die-casting lower case gives the meters a safe standing and also protection from the environment. As a special feature, both models can be upgraded with an additional module for conventional pH measurement.

Measuring stability

  • No errors with the digital signal transmission, calibration data is allocated safely, sensor data is easily transmitted. eliminates errors
  • The intelligent sensor evaluation (QSC) gives a status about the condition of the sensor and increases the operational reliability.
  • The CMC function visualizes the ideal measuring range and supports correct measuring.
  • Visual display of channels for allocation of sensors and parameters

Documentation complying with GLP/AQA


  inoLab® Multi 9420 IDS inoLab® Multi 9430 IDS
Parameter pH, mV, saturation, concentration, partial pressure, conductivity, special resistance, salinity, TDS, temperature pH, mV, saturation, concentration, partial pressure, conductivity, special resistance, salinity, TDS, temperature
Digital/IDS sensor `79; `79;
Universal measuring channels 2 3
Analog pH/Redox Sensors ADA S7/IDS (optional) ADA S7/IDS (optional)
Temperature compensation all except ORP all except ORP


Securely traceable …

… with the innovative inoLab® Multi 9310 IDS


inoLab? Multi 9310 IDS


  • A single-channel multi-paramter benchtop meter for IDS sensors
  • Digital sensor recognition
  • Optional built-in printer


WTW digitale IDS-Sensoren


The new inoLab® Multi 9310 IDS with one digital measuring channel is perfectly suited for entering the digital multiparameter measuring with the IDS Sensors. The IDS technology enables ideal measurements and efficient documentation in the most easiest and convenient way.

Measuring stability

  • Error-free processing of measuring signals in the sensor
  • Digital transmission of measuring signals and additional information
  • Automatic adoption of calibration data and parameterization

Documentation acc. to GLP/AQA


Measuring channel 1 (universal)
Display LCD graphic, backlit
Data storage Manual: 500 data sets/Automatic: 5000 data sets
Logger Manual/time-controlled
Interface Mini USB
Printer (optional) Thermo printer, width 58 mm
Power supply

Universal power supply 100 to 240 V, 50/60 Hz, 4 x 1,5 V AA or 4 x 1.2 V NiMH rechargeable battery


Portable Multi-parameter Instruments

Field Sets for Portables

Handhelds are available in convenient carry cases including sensors and accessories for immediate use. Meter sets with three sensors will be delivered in the large field case including accessories. 

New: ProfiLine Multi 3320 – Up-to-date Multi-parameter Measurement


  • Enhanced measurement functionality
  • pH, ORP, ISE, Conductivity, Dissolved Oxygen
  • For all conventional single parameter sensors

The Multi 3320 for measurement of pH, ORP, conductivity, and dissolved oxygen (electro chemical) is a perfect meter for environmental applications in ground and surface water measurement, aquaculture, waste water treatment plants and much more.

  • Two inputs for simultaneous measurement of pH and conductivity, or pH and dissolved oxygen.
  • Backlit LCD for displaying two measurements at the same time
  • For all conventional WTW pH, combined ISE, conductivity cells and electrochemical D.O. sensors

ProfILine pH/Cond 3320

The pH/Cond 3320 with two inputs for pH, ORP, ISE and conductivity measurement is an all-rounder for almost every application in process chemistry, life science, food and beverages as well as pharmaceutical industry (measurement of pH and conductivity according to pharmacopeia standards)


  • Two inputs for simultaneous measurement of pH or ISE or ORP and conductivity
  • Backlit LCD for displaying two measurements at the same time
  • For all conventional WTW pH, combined ISE, conductivity cells

The pH/Cond 3320 as well as the Multi 3320 have a robust and water proof housing (IP 67) and have also a memory with a data logging functionality between 1 s and 60 minutes. All entries are GLP compliant with time, date and selectable ID number. The modern waterproof USB interface supports fast and easy data transfer.

Technical Data pH/Cond 3320, Multi 3320

TDS 0 mg … 199.9 g/l
pH measurement pH/Cond 3320, Multi 3320
pH -2.000 ... +19,999 pH
mV -2500 ... +2500
ISE (mg/l, µmol/l, mg/kg, ppm, %) 0.000 … 999999
Dissolved oxygen measurement Multi 3320
O2 Concentration 0.00 ... 20.00 mg/l 
0.0 ... 90,0 mg/l*
O2 saturation 0.00 ... 200.0 % 
0.0 ... 600%*
Conductivity measurement pH/Cond 3320, Multi 3320
Conductivity 0.000 µS/cm ... 1000 mS/cm
Salinity 0.0 ... 70.0

* depending on D.O. sensor

General Data pH/Cond 3320, Multi 3320

  General Specifications
Calibration memory Up to 10 calibration records
AutoRead Automatic/Manual
Celsius/Fahrenheit yes
Display LCD Graphic, backlit
Memory Manual 200/5000 automatic
Logger Manual/time controlled
Waterproof IP 67
Interface Mini USB-B
Power supply 4 x 1.5 V AA oder 4 x 1.2 V NiMH-Akku
Continuous operation

Up to 800 h without/ 100 h with backlit


Unique and Distinctive: IDS Sensors

The new IDS sensors – intelligent, digital sensors – represent the next generation of WTW electrochemical sensor technology. Equipped with innovative measurement electronics, IDS sensors automatically store their unique serial number and calibration data. IDS sensors not only store data, but also process signals providing superior data integrity. This enables effective evaluation of the sensor quality by means of the Quality Sensor Control (QSC) function.

Digital IDS pH Electrodes


  • Fail-safe measuring signal
  • Calibration status in the electrode
  • Proven reliability and accuracy
  • SenTix® 940
  • SenTix® 940-3
  • SensoLyt® 900-P
  • SenTix® 950
  • SenTix® 980
  • SenTix® ORP 900
  • SensoLyt® ORP 900-P

ORP electrodes are also frequently used electrochemical sensors. They provide sensitive voltage signals. The concept of IDS sensors precisely takes effect here.
Digital data transfer without interferences allows the user to use a long cable and enables important additional information such as calibration data and sensor ID.

SenTix® 940/940-3 950 980
pH 0.000 … 14.000
± 0.004
0.000 … 14.000
± 0.004
0.000 … 14.000
± 0.004
°C 0 … 80 °C 0 … 80 °C 0 … 100 °C
SensoLyt® * 900-P ORP 900-P
pH 2.000 ... 12.000 ± 0.004
mV ± 1200.0 ± 0.2
°C 0 … 60 °C 0 … 60 °C

* Presseure resistant up to 10 bar (IP 68)

Digital IDS ORP Electrodes


  • SenTix® ORP 900
  • SensoLyt® ORP 900-P

pH/ORP electrodes are the most commonly used electrochemical sensors. At the same time, they provide the most sensitive measuring signals and must be serviced and calibrated on a routine basis. The concept of IDS sensors precisely takes effect here.
Digital data transfer without interferences allows the user to use a long cable and enables important additional information such as calibration data and sensor ID.


SenTix® ORP 900
mV ± 1200.0 ± 0.2
°C 0 … 100 °C
Sensor Platinum

SensoLyt® * ORP 900-P
mV ± 1200.0 ± 0.2
°C 0 … 60 °C
Sensor Platinum

* Presseure resistant up to 10 bar (IP 68)

Digital IDS Dissolved Oxygen Sensors

FDO® 925 – the Optical Dissolved Oxygen Sensor for Field and Lab


  • Robust and waterproof
  • Extremely fast (t99 < 60s)
  • Free of incident flow with beveled membrane
  • Factory calibrated sensor cap with intelligent chip
  • Low maintenance

The FDO® 925’s small dimensions make it suitable for lab and process. The flow-free, easy-to-clean, beveled membrane allows it to be used in containers with low sample volumes. Low oxygen concentrations under 1 mg/l can also be detected accurately.

The fast and flow-free FDO® 925 is perfectly suited for field measurement. Accessories such as protective armor made of plastic or stainless steel, make this sensor ideal for use in harsh environments. The Kevlar®- strengthened cables of varying lengths allow reliable measurements in deep lakes or raging rivers.

In the sewage plant, FDO® 925 excels at BOD measurement in the Karlsruhe bottle as well as in the monitoring of stationary measurement systems. In connection with the AutoRead function of the MultiLine® devices, its characteristics can be aligned to that of the online sensor FDO® 700 IQ and thus guarantees comparable measured values.

Concentration 0.00…20.00 mg/l ± 0.5 % of value
Saturation 0.0 … 200.0 % ± 0.5 % of value
Partial pressure 0.0 to 400 hPa ± 0.5 % of value
Temperature 0 … 50.0 °C ± 0.2 °C

Digital IDS Conductivity Cells


  • Proven sensor technology
  • Easy-to-handle
  • Wide range of applications

WTW offers decades of expertise in high quality, rugged conductivity cell technology, and now the new IDS conductivity cells build upon this proven technology including the automatic transfer of the cell constant feature to eliminate operation errors.
Two models are available to cover the entire conductivity range:
The four electrode cell TetraCon® 925 for medium and high level conductivity samples, and the two electrode cell LR 925/01 with flow-through vessel for pure-water and low conductivity samples.

  TetraCon® 925 LR 925/01
Conductivity 10 µS/cm ... 2000 mS/cm 
± 0.5 % of value
0.01 ... 200 µS/cm 
± 0.5 % of value
Specific resistance 0.5 Ohm cm ...100 kOhm cm 
± 0.5 % of value
5 kΩ ... 100 MΩ 
±0.5 % of value
Salinity 0.0 ... 70.0 
± 0.5 % of value
TDS 0 ... 1999 mg/l
0,0 ... 199.9 g/l 
± 0.5 % of value
Temperature 0 ... 100.0 °C 
± 0,2 °C
0 ... 100.0 °C 
± 0.2 °C