This program is automatically transferred to
the PMA2100 upon connection of the probe yielding immediate readings without the necessity
of configuring the meter. This approach guarantees full interchangeability of the probes
and high degree of traceability. A number of unit conversion algorithms are also programmed
into the probe simplifying its use.
The relative humidity is the ratio of the actual vapor pressure to the
saturation vapor pressure at the air temperature, expressed in percent. Relative humidity
displays an inverse relationship with absolute temperature when the vapor
pressure is held constant.
The Dewpoint calculating program is also included in the memory
capsule. The Dewpoint is the temperature the air would have if it were cooled , at
constant pressure and water vapor content, until saturation (or condensation) occurred.
A temperature compensated capacitive sensor is used in the PMA2170 to
achieve high accuracy and long term stability over a broad range of environmental
conditions. The sensor exhibits low hysteresis. A membrane filter and housing protect the
sensor from contaminants. The humidity sensitive capacitive elements for this probe
are manufactured to very tight specifications and factory-calibrated allowing simple
replacement, should the sensor get damaged. No additional calibration is necessary.
Humidity is a very important factor for the comfort of humans and
animals, operating sensitive electronic equipment, working with high voltage or static
sensitive components. Fabrics, adhesives and paper change their properties with the
ambient humidity. Even some precision mechanisms might be affected by humidity.
Comfortable room relative humidity at 20-25°C is around 50% RH. It may vary from 38%
RH in class-10 clean rooms to 60% RH in hospital operating rooms.
