Michell Instruments - Moisture, Humidity and Gas Analysis Instruments

Michell Instruments is the international leader in the field of moisture, humidity measurement and gas analysis. With over 30 years' experience of designing precision instrumentation, Michell offer a number of solutions for the power industry that can help ensure safety, increase the lifetime of equipment, improve efficiency and save money.

Oxygen analysers – XZR 500 flue gas analyser

The XZR 500 oxygen analyser from Michell Instruments is designed to determine the excess of air required for optimum combustion. The zirconium oxide sensor was originally developed for measuring the levels of oxygen in volcanoes and can withstand extremely harsh conditions such as:

• Combustion and control efficiency in boilers
• Emissions monitoring (Mcert and NFIE certified)
• Coal-fired power plants
• Petrochemical furnaces

Anti-icing systems for gas turbines

An anti-icing system is vital to prolong the life of gas turbines located in low-temperature environments, where there is a risk of ice forming in the air intake systems. Ice can cause anything from loss of power, through blockage of the filter and reduction of air-flow, to physical damage to the turbine if chucks of ice get ingested into the compressor.

A key part of any anti-icing system is a hygrometer to monitor the humidity and dew point of the air, and to provide alerts when there is a risk of ice forming. The Optidew hygrometer for anti-icing systems has been designed specifically for this purpose. Applying the fundamental cooled-mirror measurement principle, it delivers a repeatable, drift-free dew point or relative humidity measurement.

The robust design of the new Optidew hygrometer for anti-icing systems is capable of withstanding the most demanding conditions and guarantees minimal maintenance while retaining the performance and sensitivity of a high-level laboratory reference hygrometer.

When compared to a traditional polymer RH probe, the Optidew anti-icing version offers far better accuracy and stability. It has a wide dynamic measurement range from –50°C to +90°C dew point over a temperature range of –10°C to +90°C and has been successfully tested in the extreme atmospheric conditions.

Hydrocarbon dew point analyser for reduced downtime

In CCGT power plants, accurate measurement of hydrocarbon dew point in fuel gas allows a minimum superheat to be selected, which means that the risk of flame back-up through condensate formation is reduced.

Condumax II is a fully self-contained hydrocarbon dew point analyser, using the proven "dark spot" hydrocarbon dew point measurement principle from the highly successful Condumax instrument. Combining a hydrocarbon dew point cell and water dew point measurement in the same compact and lightweight EExd enclosure, Condumax II requires nothing more than mains power to operate. Condumax II provides a continuous local indication of key measurements in addition to analogue and digital outputs for remote monitoring.

High voltage switchgear

Moisture in sulphur hexafluoride (SF6) arc quenching gas can cause rapid and severe deterioration of high-voltage switchgear. It is vital to check the moisture content of new SF6 in cylinders by industrial gas producers prior to use, including dry gas purging of new switchgear enclosures, in service field checks, and continuous monitoring.

The Cermax portable dewpointmeter from Michell Instruments provides very quick spot measurements of dew point down to -60°C, making it ideal for checking the dew point of the SF6.

Analysis of moisture in hydrogen coolant

Measurement of moisture in hydrogen being used to cool electrical generator sets ensures that the dew point of the hydrogen does not rise above ambient temperature causing condensation and thus the danger of damaging the generator. The upper limit is usually 0°C dew point.

The Easidew TX I.S. from Michell is a simple, rugged and cost effective dew point transmitter. Certified to ATEX for use in explosive gases, it can easily be incorporated into an ES10 sampling system to provide a complete solution for hydrogen monitoring with generators.