For monitoring leaks of ammonia in aqueous solutions

This sensor can be used to measure ammonia (NH3) in aqueous solutions. In an aqueous solution, ammonia is in a pH-dependent equilibrium with ammonium ions (NH4 + ions). Provided the NH4 + ions are converted into ammonia by adding lye, the sensor also detects the resultant ammonia. The NH4 + ions themselves are not detected. The ammonia sensor consists of a pH glass electrode and a reference electrode. Both the electrodes are in an electrolyte. The electrolyte is separated from the process medium by a hydrophobic, gas-permeable membrane. The pH value of the electrolyte changes if NH3 gas diffuses through the hydrophobic membrane. This local change in the pH value is measured at high resistance by the integrated pH electrode. JUMO ammonia sensors feature the advantage of having ready-made membrane caps. There is no need to put the sensitive membrane on by hand. With the JUMO sensor, the membrane cap is quickly and easily replaced as a complete unit.

Monitoring ammonia leakage in refrigerating plants

Refrigerating plants (in indoor ice rinks or cold storage, for example) frequently use ammonia as a refrigerant. As ammonia (NH3) is a toxic, pungent-smelling, colorless gas, the plants are monitored for escaping ammonia (leakage). Gas sensors are used to monitor the ambient air (these are not supplied by JUMO). In addition, the pipes and system components that carry the liquids are monitored for ammonia ingress. JUMO's ammonia-sensitive sensor can be used for this purpose. Measuring ammonia with a JUMO ammonia sensor gives a far more selective response than measuring the pH. The JUMO ammonia sensor can also be used in online analyzers/samplers or in the laboratory. More information can be found in JUMO white paper 631, "Information on measuring ammonia in water".