Endress+Hauser are committed to the long term support of all our products
We undertake support and service for our products for a period of ten years after notice of product withdrawal (until spareparts are not available any more)
However we reserve us the right to offer alternative solutions including replacement products if deemed more appropriated.
Product status
Product rootQMW43
NameLiquid Analysis
Physical Medium Properties
Liquitrend QMW43
Process temperature-10 °C to 110 °C (14 °F to 230 °F) Sterilization: max. 130 °C at 6 bar abs up to 60 min (Max. 266 °F at 87 psi up to 60 min)
Process pressure13 bar abs up to 50 °C (188.5 psi up to 122 °F) 7.75 bar abs at 110 °C (112 psi at 230 °F) 6.0 bar abs at 130 °C for max. 60 minutes (87 psi at 266 °F for max. 60 minutes)
Measuring rangek=0,01: 0.04 to 20 µS/cm k=0,1: 0.10 to 200 µS/cm
Process temperatureThreaded with fixed cable: -20 to 100 °C (-4 to 212 °F) Threaded with plug-in head: -20 to 120 °C (-4 to 248 °F) Sterilization: max. 140 °C (284 °F) for 30 minutes
Process pressure13 bar at 20 °C (188 psi at 68 °F) absolute 2 bar at 120 °C (14 psi at 248 °F) absolute
Input1 to 2x Memosens digital input 2x 0/4 to 20mA input optional 2x Digital input optional
Output / communication2 to 8x 0/4 to 20 mA current outputs Alarmrelay, 2x relay, ProfibusDP, Modbus RS485, Modbus TCP, Ethernet
Ingress protectionIP66 / IP67
Conductivity sensors and transmitters
Our product finder helps you to search for suitable measuring devices, software or system components via product characteristics. Applicator leads you through an individual product selection via application parameters.
In many applications conductivity is crucial for process control, product monitoring, water monitoring, or leakage detection. We provide reliable and accurate instruments for all measurement ranges and conditions, such as ultrapure water, CIP cycles, hazardous areas or hygienic processes. Check out our broad offering of conductive and toroidal conductivity sensors, transmitters and helpful calibration tools by clicking on the button below.
How to select conductivity sensors
Conductivity sensors and transmitters are used in many industries such as food & beverage, chemicals, life sciences, pharma, water and power. The sensor selection depends on the application and the conductivity range. To measure low conductivities in pure and ultrapure water, choose conductive sensors. Use toroidal sensors in media with high conductivity (e.g. milk, beer, bases, acids, brine) and apply 4-electrode sensors where a wide measuring range is required (e.g. phase separation).
The conductivity of a liquid can be measured using the conductive or toroidal measuring principles. This video shows what it is about and how these measuring principles work.
The four-electrode conductivity measurement is suitable for broad measuring ranges or when the ion concentration in a liquid is very high. This video shows how the measuring principle works.
Conductivity measurement with conductive sensors
Conductive probes feature two electrodes that are positioned opposite from each other. An alternating voltage is applied to the electrodes which generates a current in the medium. The intensity of the current depends on the number of the medium's free anions and cations that move between the two electrodes. The more free anions and cations the liquid contains, the higher the electrical conductivity and the current flow. The conductivity unit is "Siemens per meter".
Conductivity measurement with conductive 4-electrode sensors
A high ion concentration in the medium leads to a mutual repulsion of the ions and thus a reduction of the current - the so called polarization effect. This can influence the measuring accuracy of conductive probes. 4-electrode sensors have two electrodes that are currentless and therefore not affected by the polarization effect. They measure the potential difference in the medium. A connected transmitter uses the measured potential difference and current to calculate the conductivity value.
By choosing the Liquiline platform, you’re effectively choosing to spend less money on stock holding, save installation time and gain operational safety!
