JUMO 202820 Polypropylene Immersion Fittings for pH, Redox and Conductivity Sensors

Immersion fittings that hold pH, redox and conductivity sensors in open channels and tanks

The JUMO 202820 series of immersion fittings holds electrochemical sensors, such as pH and redox electrodes, glass conductivity cells and compensation thermometers, that have a Pg 13.5 screw-in thread and a fitting length of 120 mm. The fittings are mounted in open sluices, channels or containers, protect the installed sensor from breaking and allow measurement at different immersion depths. Two designs exist: type 202820/40 with a 40 mm tube for one sensor and type 202820/63 with a 63 mm tube for up to three sensors. Both are made of polypropylene with FPM seals, are rated for 0 to 95 degC and 1 bar up to 90 degC, and come with pipe clips for wall or channel mounting.

Technical specifications

Accessories and installation planning

Flanges let the fitting stand in container lids: DN 32 (00083375) and DN 50 (00083376) for the 40 mm fitting, DN 50 (00056544) and DN 65 (00056545) for the 63 mm fitting. Wetting cups keep a residual liquid around the electrode so that pH and redox sensors do not run dry when the container is empty: 00083372 for the 40 mm fitting and 00057581 for the 63 mm fitting. A shackle (00453191) allows suspended mounting of the 40 mm fitting, and a pressure-tight KCl reservoir (00060254) for wall mounting supports an electrolyte bridge or KCl-filled electrodes with pressure up to 6 bar. For use with JUMO digiLine electronics the 63 mm fitting can be fitted with a dedicated connection head, part no. 00666612.

The datasheet lists points the planner must observe. The fitting must be readily accessible so the sensor can be cleaned and serviced regularly, pH and redox electrodes must not stay dry for long, and the system designer must test chemical compatibility of the materials. Cleaning nozzles with a DN 12 hose connection (extra code 078) are offered for fittings in dirty basins, and a grounding rod (055) provides equipotential bonding in insulated plastic containers.

Choosing the right fitting and companions

Construction differs between the two types. The 40 mm fitting has a protection tube, an electrode holder at its lower end and a protection basket, with the cable leaving through an M25 x 1.5 fitting and a pipe clip for fixing. The 63 mm fitting has a connection head about 102 mm in diameter with three Pg 7 glands, a spacer ring, a pipe clip and a protection basket. The standard immersion tube lengths in the order code run from 500 mm to 2000 mm, with 500 mm and 1000 mm normal for type 40 and 500 mm available ex-stock for type 63. The datasheet shows two standard installation options: fixing with pipe clips in an inlet channel, and fixing with a flange on a container, where a wetting cup keeps the sensor from running dry in an emptied tank. An external KCl reservoir can be used with all immersion fittings, which supports an electrolyte bridge or KCl-filled electrodes.

Choose type 40 for a single electrode and type 63 for combinations such as pH, redox and a compensation thermometer in one tube. Other JUMO fitting families are referenced for different duties: flow-through fittings (202810), process immersion fittings (202821), manual quick-change fittings (202822) and stainless steel process fittings (202825).

For sensors that fit these fittings see the published dTRANS pH 02 and AQUIS 500 pH measuring chains, and browse liquid analytical accessories for more. In an enquiry give the sensor type and thread, the number of sensors, tube diameter, immersion length, medium temperature and any extra codes such as KCl reservoir or cleaning nozzle.

Related JUMO products: JUMO tecLine Ci-S Inductive Conductivity Sensor, JUMO tecLine CR Conductive 2-Electrode Conductivity Sensor, JUMO 907032 Hygrostat for Room and Duct Humidity Control, JUMO AQUIS 500 Ci Inductive Conductivity Transmitter, JUMO 909740 Replacement Measuring Inserts for Screw-In RTD Probes and Thermocouples and JUMO AQUIS 500 pH pH/ORP Transmitter and Controller.

Installation options described by JUMO

The JUMO data sheet 202820 shows three ways of installing these fittings: fixing with pipe clips in an inlet channel (two pipe clips for wall mounting are supplied with the standard versions); fixing with an optional sliding flange on a container lid; and use of a wetting cup, so that residual liquid stays around the sensor when the container is empty and the sensor does not run dry. JUMO also notes that an external KCl reservoir can be used with all immersion fittings, and that the system designer must check the chemical compatibility of the materials with the medium.

Documents and quotation

Hosted for reference is the official JUMO data sheet 202820, version 3.00 dated 2019-08-17, eight pages in English, with dimensions, extra codes, order details, stock versions and accessories. Seven Star LLC is an independent supplier in Muscat; send the order code and we will prepare a quotation.