Heavy Duty Sensor & Modular Analyzer

Rather than thin bodied lab grade sensors commonly offered,  we use only sensors designed to withstand the conditions found in wastewater treatment plants and industrial processes.

Various compounds available for the solid state reference system with double or triple junctions provide resistance to the compounds and temperatures that can kill standard sensors, allowing you to focus on your process and not your sensors.

The modular analyzer design gives you the flexibility to configure the FX-300 as a simple ammonium transmitter, a pH compensated total ammonia analyzer, or a multi-parameter analyzer for any combination of measurements such as ammonium, pH, conductivity, ORP in one enclosure.

Each separate measurement and function module includes a 3 digit LED display of ppm and temperature and scalable 0/4-20mA output. Optional RS-485 Modbus RTU output is available and comes standard with the pH compensation module.

Ion operating ranges are selectable between 0-10, 0-100 and 0-999ppm.

A special high range "K-PPM" option allows you to measure from 0-10,000 to 0-999,000ppm.

The system is very easy to operate using three buttons on the face of each transmitter. The actual sensor millivolt (mV) output can be displayed by pressing the down button while in ppm mode.

More options include support for integral or external signal preamplifiers for long cable runs or noisy environments, alarm relays with basic control functions, temperature output and data logging.

Ion Compensation Can't Work

A unique membrane and solid state reference system in the electrode provides improved life and more selectivity over potassium, which interferes with the measurement.

The sensor can measure ammonium in the presence of 20 to 30 ppm potassium ions while maintaining linearity and stability under the most common conditions found in wastewater treatment.

Some systems include a second potassium ion sensor in an attempt to compensate for the interfering ion.

Ion compensation doesn't work reliably in continuous field applications given the variance of these factors:

Constant exposure to the interfering ion beyond a sensor's capability deteriorates the electrode, affecting the reading itself while gradually reducing its output.

Process streams can have varying sample background, analyte and interfering ion levels as well as temperature.

Uncertainties inherent to sensors as well as the calibration accuracy of the three sensors involved tend to compound any error instead of reducing it.

Continuously changing process inputs are too complex to be corrected with a formula, and extremely difficult to account for in a laboratory much less in an online application.

Total Ammonia

Dissolved ammonia gas converts into the ammonium ion form in a reaction dependent upon pH and temperature.

The sensor can only measure free ammonium ions (NH⁺4) . But given the pH and temperature relationship, the total ammonia (NH3 + NH⁺4) can be calculated using an ammonia gas resistant pH sensor and pH compensation module FX-300-TOT.

The system, shown above, displays free ammonium, pH and total ammonia.