JUMO tecLine CR S01 Compact Two-Electrode Conductivity Sensor, Type 202928

A compact conductivity sensor for small pipes and tight installations

The JUMO tecLine CR S01 (type 202928) is a conductive two-electrode conductivity sensor in a compact housing based on a cable fitting to DIN EN 62444. Stainless steel 1.4404 electrodes sit in a PEEK base with high chemical resistance, and an integrated Pt100 or Pt1000 probe measures the liquid temperature at the same time. Immersion lengths between 22.5 and 44.5 mm let it fit small nominal pipe widths and hard-to-reach positions. Two cell constants cover a wide span: K = 1.0 for 1 to 5000 uS/cm and K = 0.1 for 0.1 to 1000 uS/cm, and the stated working temperature runs from -40 to +100 degC. Typical uses include reverse osmosis plants, cooling and air-conditioning circuits, drinking and process water, and food and beverage rinsing.

Technical specifications

Which process connection material to choose

The datasheet includes a selection guide and states that the user must verify suitability. Nickel-plated brass resists aqueous and alkaline solutions, non-oxidising acids, neutral salt solutions and organic substances, but is not suitable for swimming pools, seawater, brackish water or soft water with a high chloride content. Stainless steel 1.4404 resists organic and inorganic acids and moderate chlorine and salt concentrations (chlorine resistance limited to 4 mg/l), suits hygienic, food, beverage, brewery and dairy duty, and is not resistant to seawater or solutions with high hydrogen sulphide content. Because the electrodes are 1.4404, chloride ions must not exceed 1000 mg/l in cold water or 500 mg/l in heated indoor and open-air swimming pools.

In practice this means choosing the thread and metal together: M20 x 1.5 allows either steel or brass, while 1/2 in NPT is offered in nickel-plated brass in the order code. The fixed 5 m cable ends in ferrules for the transmitter terminals, and the shield is connected at the transmitter side.

Suitable transmitters and enquiry details

The sensor connects to the JUMO ecoTRANS Lf 01/02 (data sheet 202731), Lf 03 (202732) and Lf 04 with Modbus RTU (202733) on a DIN rail, to the dTRANS CR 02, to the AQUIS 500 CR, and to the AQUIS touch P and S (202580 and 202581), see also the published AQUIS touch P. The liquid analysis sensors category lists further sensors. When you enquire, give the conductivity range (to select K = 0.1 or 1.0), medium and its chloride and oxidant content, temperature, pressure, pipe size, thread, connection material, temperature probe type and the transmitter to be used.

The two design types differ in geometry and cell constant, so check the dimensional drawings for the body length of each. Because a conductive cell polarises when it is pushed outside its typical range, the datasheet advises choosing the cell constant to match the expected conductivity and notes that the cell constant can be corrected at the transmitter when production tolerance moves it by up to 10 %. The sensor housing carries a nameplate and a nickel-plated brass or stainless steel cable fitting.

Typical applications named in the datasheet include drinking, service and wastewater, refrigeration and air-conditioning, reverse osmosis, industrial rinsing with low pollution, horticultural technology, the chemical industry, and food and beverage production. The housing is easy to clean and the compact design with metric or NPT thread is intended to make mounting simple and reliable.

Related JUMO products: JUMO tecLine CR Conductive 2-Electrode Conductivity Sensor, JUMO tecLine Ci-S Inductive Conductivity Sensor, JUMO tecLine Br Amperometric Bromine Sensor, Type 202637, JUMO ecoLine O-DO Optical Dissolved Oxygen Sensor, Type 202613, JUMO tecLine pH Process pH Combination Electrode and JUMO tecLine Cl2 Free Chlorine Sensor.

Measuring principle and typical applications

JUMO data sheet 202928 explains that the tecLine CR S01 measures electrolytic conductivity by the conductive two-electrode principle. The transmitter applies an alternating voltage to the electrodes, and the current through the medium depends on its conductivity. An integrated Pt100 or Pt1000 probe measures the liquid temperature at the same time, so the transmitter can compensate the reading. The K = 1.0 version covers 1.0 to 5000 µS/cm, and the K = 0.1 version covers 0.1 to 1000 µS/cm, which suits low-conductivity water such as reverse osmosis permeate. JUMO lists typical uses as drinking water, service water and wastewater; refrigeration, air-conditioning and cooling systems; reverse osmosis plants; industrial rinsing processes with a low level of pollutants; horticultural technology; industrial water; the chemical industry; and food and beverage applications.

Documents and quotation

Hosted for reference is the official JUMO data sheet 202928, version 2.00 dated 2025-01-10, six pages in English, with the selection guide, technical data, dimensions, wiring and order code. Seven Star LLC is an independent supplier in Muscat; send the order code and we will prepare a quotation.