Ion Selective Electrode for Ammonium

NH4+

Technical Data Sheet

Structure of the Electrode

range*:
  • 10-5 to 1 mole amonium
  • 0.18 to 18,000 mg/L ammonium

The ammonium selective electrode is a matrix membrane electrode with a solid contact or a liquid contact. The flexible ammonia selective membrane is made from a special organic ion exchanger which is dissolved in an organic solvent and embedded into a PVC matrix.
As an organic phase the resulting "liquid membrane" is fixed by the PVC matrix and renders a stable phase boundary.
An inner electrolyte (only for electrodes with a liquid contactor) (0.1 mole/L moonium chloride NH4Cl or a solid contactor forms the discharge contact for the equilibrium voltage which develops at the phase boundary.
Both the shaft and the ion selective membrane are made from PVC. This should be taken into account when using the electrode.

Ordering Information

PO No. Type Description
118 100 NH4 selective electrode with 1m sealed cable
118 101 NH4 selective electrode with 1m sealed cable with BNC connector
118 102 NH4 selective electrode with 1m sealed cable with DIN connector
118 005 NH4 selective electrode with indutrial threaded head
119 004 NH4 selective threaded mini electrode with BNC connector
slope of characteristic:
  • 57 (+-)2 mV/pNH4
response time in 10-2mole,
180 mg/L ammonia solution:
  • < 30 sec
drift within 30 minutes:
  • 0.3 mV
drift within 24 hours:
  • 1 mV
concentration of interfering ion species:
  • K+: 10 times
  • Na+: 103 times
  • Mg2+: 104 times
  • Ca2+: 104 times
  • H+: 102 times
pH range:
  • 3 - 7
temperature range:
  • 0 - 40 °C
resistance:
  • < 1 MOhm
sensor material:
  • organic ion exchanger in a special solvent, homogeneously distributed in PVC
shaft material:
  • plastic
dimensions:
  • immersion depth 120mm
  • diameter 12 mm
* approximate values, depend upon specific application