In-Situ Ammonia measurement AmNiSys

In-situ Ammonia measurement

The AmNisys is an ion selective electrode monitor for ammonia measurement in all areas of waste water. It is normally supplied in an enclosure complete with integral compressor for air cleaning of the electrodes.

A low-cost, in-situ combination Ammonia measurement system with a proven track record in wastewater applications.

Its unique membrane provides a robust measurement performance as the electrodes respond more accurately to ammonia. For known and unavoidable interferences, such as potassium, automatic compensation can be made with integral ISE sensors.

It is simple to deploy and is ideal for “in-process” monitoring, and is our recommended option for inlet monitoring.

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ammonia measurement in mixed liquor
ammonia measurement

Features and Benefits

  • Automatic air cleaning
  • Optional auto-compensation for interfering ions
  • Single or multiple parameters including NH4-N, pH, K, CL-
  • Graphic display from up to 4 sensors
  • 4 x analogue outputs, 5 configurable relays, RS232, optional PROFIBUS
  • Fully serviceable low-cost sensors, no sensor replacement necessary
  • Digital data transmission from sensors


  • Optimal SBR control for nitrification/denitrification
  • Complete mix and plug flow aeration control
  • Return liquor control for ammonia load-balancing
  • Effluent quality surveillance



  • Operation Principle: Ammonia selective electrode, Nitrate-selective electrode, compensated for Potassium, Chloride, pH and temperature
  • Ranges: 0.1 - 1000mg/l NH4-N / 0.1 - 1900mg/l NO3 / pH 2-12 / Temp 0-40deg C
  • Resolution/Repeatability: dependent on parameter
  • Accuracy: 5% of full-scale
  • Response time: 95%<1m
  • Calibration: Manual, single-point, offset or 2-point calibration in simple matrix
nirtate and ammonia measurement


  • Dimensions:255(h) x 215(w) x 120mm(d)
  • Weight: 2.5kg (approx)
  • Ambient temp: 0-50degC
  • Weather protection: IP65
  • Display: Numeric/graphic LCD
  • Current Loop: 4 x 4-20mA into 500 Ohms
  • Relay Outputs: 5 x use-configurable relays (6A@250V)
  • Data Interface: RS232 C (PC/laptop) RS485 for NAS760
  • Inputs: up to 2 separate probes normally
  • Parameters: up to 4 normally max of 3 per probe
  • Power: 100-240VAC
  • Load: 15VA max (excluding optional cleaning compressor)
wastewater ammonia measurement

Sensor assembly (probe)

  • Dimensions: armature dia 75mm x 125mm length
  • Weight: 4.5kg approx
  • Materials: armature - polyethylene
  • Connections: 1/4" push-fit air line, RS485 signal line
  • Electrodes: Ion-selective, and reference
  • Electrode Dimensions: 12mm diameter x 120mm length
  • Electrode Materials: POM, reference: Quartz glass
  • Reference: Ag/AgCl
  • Electrolyte: KCI
  • Junction: double chamber electrode with bridge
nitrate and ammonia measurement