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PRO2Sensor (IHT)
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Installation Manual
The PRO2Sensor (IHT) oxygen sensor design provides a low cost and easily installed in situ boiler flue stack oxygen monitoring system. The integrated intelligent in-head transmitter eliminates the need for an external signal conditioning unit that would normally be housed in a separate panel. All processing of the zirconium cell signal is carried out within the unit, and an industry standard 4 - 20mA output representing the measured oxygen level is directly available on the rear connector. The measurement cell solid state electrolyte consists of an impermeable zirconium dioxide ceramic unit stabilised with yttrium oxide ensuring stable wide band performance. Gas permeable platinum electrodes are utilised and the side exposed to the exhaust gases has a porous ceramic layer (Spinell coating) to protect against contamination. A slotted metal tube guards the ceramic body against impacts and thermal shocks. Additionally a sintered stainless steel filter protects the sensor from particulates. An internal heater maintains the cell at optimum operating temperature independently from the flue gas temperature ensuring high accuracy and rapid warm up.

The non extractive in situ installation reduces maintenance requirements to a minimum for reliable continuous monitoring, with no pumps, filters or water separators to service. Sensors are supplied pre-calibrated (Test gases traceable to NPL standards) and service exchange sensors are available. No on site calibration is required, the oxygen sensor reading being checked against a portable analyser during routine maintenance.

Measuring depleted Oxygen levels in the flue gas has long been recognised as one of the best measures of combustion efficiency and is an essential tool in reducing fuel costs and improving environmental performance of new and existing industrial boiler plant. The optimum air to fuel ratio is critical to efficient energy conversion and to minimising noxious emissions. Burning less fuel produces less Carbon Dioxide (CO2). The gross combustion efficiency and CO2 concentration can be easily calculated for any fuel type from a knowledge of excess air and flue temperature.

Correct air fuel ratio reduces the risk of flame impingement and resultant failure of boiler tubes. Combustion efficiency tests carried out during routine servicing does not protect against interim faults developing. Poor combustion accelerates the formation of carbon deposits on the heat transfer surfaces reducing efficiency and increasing thermal stress leading to boiler damage.

The PRO2Sensor (IHT) oxygen sensor is supplied with a mounting flange which is welded into the boiler flue stack. A flue stack gas probe, which is screwed into the flange, is locked in place with a lock nut. This part of the installation is permanent. The PRO2Sensor (IHT) oxygen sensor mounts on to the probe body ensuring easy accessibility for maintenance. Options include a flue stack gas temperature probe mounted into the flange, power supply for the sensor heater and pre-conduited  cable assembly for ease of installation. Please contact us for details.

Ideal for interfacing with BMS and SCADA systems, the PRO2Sensor (IHT) is supplied to a wide range of OEM and end users. Developed specifically for ease of maintenance, many of the components are recyclable, and pre-calibrated service exchange units from Conford Electronics set a new benchmark for ease of servicing and low cost of ownership.

The PRO2Sensor (IHT) is also suitable for process control in bakery ovens and heat treatment furnaces when oxygen depletion is an important parameter to monitor.


Conford, Liphook, Hampshire, GU30 7QW, UK
+44 (0)1428 751469
Webmaster: John
PRO 2Sensor (IHT) Oxygen Sensor

Field proven oxygen sensor with integrated intelligent in-head transmitter (IHT)
Providing a low cost solution to combustion efficiency monitoring
PRO2Sensor (IHT)