Ammonia Monitor for Wastewater


The MS3500 is the first ammonia monitor for Raw Waste Water. Its rugged construction and design allows it to reliably measure Ammonia at the very front end of a waste water treatment plant, giving the operator a level of control and knowledge presently unknown to the industry. It is used to:

  • Monitor Raw Wastewater Intakes
  • Detect high loads of ammonia at the intake
  • Optimise the use of compressors and blowers in the aeration lanes
  • Monitor ammonia at the effluent
  • Monitor ammonia in the aeration lanes
  • Identify serial offenders

Key Benefits

  • No sensor cleaning
  • Works at Raw Waste Water Inlets
  • No filters needed
  • Minimum maintenance (every 3 to 6 months depending on water quality)
  • Stable and reliable measurement
  • Not affected by fouling, turbidity and suspended solids
  • Reagent costs less than £100 per year
  • Does not block
  • Alarms to SCADA and other communications interfaces
MS3500 Ammonia Monitor

For a quick introduction to the system, please watch the video below:

Technical Specifications

Spec Value
Dynamic Range 1 ppm – 200 ppm in water
Absolute Accuracy Ammonia in Water: ±10%
Repeatability Repeated measurement, 5ppm Ammonia in Water: ±2%
Sampling Frequency 60/30 minutes (Contact us for other sampling periods)
Relays 2x, User Programmable function
Analogue Output 4 – 20 mA, Loop Resistance 40 Ω – 1k Ω
Digital Outputs Modbus, Profibus as options
Typical Power Consumption 70 W in normal operation
NaOH Requirement 10 l of 1 M NaOH per 15 Weeks
Enclosure GRP IP67
Operating Temperature 1 °C – 50 °C

The MS3500 features on Dutch Television

In July 2019 the MS3500 ammonia monitor featured on Dutch Television as part of a documentary on innovative water treatment technologies. Thanks to the support of our Dutch distributor, Technische Alliantie, the MS3500 has now been seen by tens of thousands of people all over the Netherlands.

The video describes how the ammonia monitor is used to measure levels of ammonia in a wastewater plant, using a contactless technology, based on the e-nose sensor and Henry's Law.

"This is a great advantage for the operators who don't need to worry about expensive cleaning routines associated with traditional ISE sensors."

Related Case Studies

Ammonia monitor at WWTP

Coming soon

Ammonia monitor at WWTP in London

Read Case Study

Ammonia monitor at the effluent of a WWTP

Coming soon

Principle of Operation

The MS3500 utilises a contactless measurement technique based on Henry’s Law, sensing headspace gases or volatiles in the sampling tank provided, and provides a measurement system with very low maintenance requirements.

Thanks to the clever design and technology the sensor never touches the water. This results in no sensor cleaning , reduced drift, virtually no fouling and very low maintenance.

The MS3500 is accurate to low ppm concentrations and its wide dynamic range allows it to be used in a wide variety of environments. Using minimal reagents and consumables the running costs of the system are very low.

The MS3500 is accurate from 1 to 200 ppm and its wide dynamic range allows it to be used in many applications.

A sample of gas is then taken from the headspace, passed through the sensor and the response analysed to provide a concentration in ppm of the ammonia in the water (Fig. 2).


Title Type Format
MS3500-SYS Wastewater Ammonia Monitor Datasheet Datasheet PDF
MS3500-SYS Installation Manual (Contact Us) Manual PDF
MS3500-SYS Operation Manual (Contact Us) Manual PDF
Press Release - Ammonia Monitor Trial Completed Case Study PDF
Ammonia monitor (Raw wastewater Inlet) Case Study PDF