Michell Instruments S8000 Chilled Mirror Hygrometer

The Michell Instruments S8000 chilled mirror hygrometer provides a direct measurement of dew point, temperature and pressure. Dew point measurement is based on the proven, fundamental optical chilled mirror measurement principle, giving long-term, drift-free humidity measurement over the entire operating range. The S8000 hygrometer uses this measurement to offer a range of available measurement units including ppm_v, absolute humidity, relative humidity and ppm_w.

The S8000 uses the RRS optical system to detect very small changes in the quantity of moisture condensed on the mirror surface, resulting in very high sensitivity and fast response to changes in frost point, even at low levels of moisture.

The S8000 features the frost assurance technology (FAST) that guarantees all dew point measurements below 32°F (0°C) are made over ice. The FAST system works by detecting whether the mirror is at a temperature where supercooled water could form and if so, rapidly cooling the mirror until a film of ice of predetermined thickness forms. Once ice has formed, control returns to the instrument, and measurement can begin.

The S8000 also uses a system called DCC (Dynamic Contamination Correction). The DCC system is intuitive and adapts the instrument control to the operating conditions to achieve optimum measurement performance at all times by periodically rebalancing the optics to compensate for any reduction in light intensity caused by contamination of the components in the optical path. Although the DCC system is fully automatic, it can be configured by the user for individual applications.

To further improve the accuracy of pressure-derived, calculated values (ppm_v, ppm_w, and absolute humidity), an optional internal pressure transducer can be supplied, which provides real-time pressure. This allows for continued humidity measurement stability even during fluctuations in sample pressure.

A pair of adjustable, isolated alarm contacts allows the S8000 to be used for direct process control. A high-contrast touch screen LCD display provides entirely customizable local indication of the measured values, along with a trend graph and fault warnings.

Michell Instruments S8000 Chilled Mirror Hygrometer Applications

• Standards laboratory reference instrument
• Transformer vacuum drying verification
• Clean/dry room environmental monitoring
• Metallurgical process monitoring
• Reference instrument for commercial calibration laboratory
• Compressed air dryer R&D
• SF₆ switchgear moisture testing
• Hydrogen fuel cell R&D