JUMO tecLine Br Amperometric Bromine Sensor, Type 202637

A bromine sensor for pools, cooling water and seawater disinfection control

The JUMO tecLine Br (type 202637) is a membrane-covered, amperometric sensor that measures hypobromous acid (HOBr) in water. It works on the potentiostatic three-electrode principle with electronics integrated in the sensor, and it is offered with either a temperature-compensated 4 to 20 mA output (202637/61) or a digital Modbus RTU interface (202637/71). JUMO names drinking water, swimming pool water, service water, process water, cooling water and seawater as application areas, and the sensor suits both free bromine (HOBr) and bromine released from BCDMH (1-bromine-3-chlorine-5.5-dimethyl-hydantoin). The datasheet states that it is not suitable for detecting the absence of bromine.

Technical specifications

Selecting the output type and range

Choose 202637/61 where the sensor feeds a standard-signal input such as the dTRANS AS 02 or the AQUIS 500 AS, and 202637/71 where a Modbus RTU master, the AQUIS 500 RS or the AQUIS touch S/P is available. Order codes follow the pattern 202637/61-37, with 20 meaning 0 to 2 mg/l and 37 meaning 0 to 20 mg/l. The datasheet warns that the slope of the 4 to 20 mA sensors can vary between 65 % and 150 % of nominal, so the concentration to be measured should be multiplied by 1.5 before the range is chosen; its example turns 1.6 ppm into 2.4 ppm and a 5 ppm range. The order code is not modular, and freely chosen combinations need technical release from JUMO.

Operating conditions matter as much as the range. The bromine sensor needs a continuous sample flow of at least 15 cm/s, which the JUMO combination fitting or individual fitting guarantees when paired with the flow monitor, and it must stay in a suitable flow fitting. Calibration needs a photometric test set; DPD-1 is named for free bromine and DPD-4 for bromine from BCDMH. Use one disinfectant at a time, because chlorine, chlorine dioxide and ozone are all registered by this sensor.

Installation, maintenance, spares and applications

Check the measuring signal at least weekly, replace the membrane cap about once a year depending on water quality, and renew the electrolyte every three to six months. The sensor can be stored dry without electrolyte between +5 and 40 degC, and the electrolyte keeps at least one year in its original bottle away from sunlight. One spare parts set (membrane cap and fine abrasive paper) is listed as part no. 00673877 and the special electrolyte (100 ml) as 00673876. Fittings include the combination fitting 00607325 with integrated flow monitor and mini ball valve, the individual fitting 00392611, its mounting bracket 00455706 and the flow monitor 00605507. Digital sensors on an AQUIS touch S/P need the JUMO digiLine hub 00646871 and an external supply such as 00661597.

Typical uses are swimming pool water, cooling-water circuits and seawater applications where bromine is preferred to chlorine for its lower corrosive effect and milder odour, as the datasheet describes. For related measuring points see the published AQUIS 500 CR for conductivity, the dTRANS pH 02 for pH and the ecoLine NTU turbidity sensor, or browse liquid analysis sensors for further probes. A useful enquiry names the disinfection method, expected bromine concentration, pH and conductivity of the water, temperature, pressure at the sensor and the required output.

Documents and quotation

Hosted for reference is the official JUMO data sheet 202637, version 2.00, nine pages in English. It contains the technical data, dimensions, wiring, order details, manufacturing versions and accessory part numbers. Seven Star LLC is an independent supplier in Muscat; send the type code, range and output, and we will prepare a quotation.