Super Systems 1500 VRSD - Manual (Page 4)

Model 1500 VRSD Operations Manual
Super Systems Inc. Page 4 of 28
Introduction
The 1500 VRSD (Part Number 13599 and 13671) is an SSi Standard System designed to maintain
a consistent atmospheric dew point by monitoring dew point measured by a dew point sensor
and using an SSi 9125 Controller to control the process. A 3.5” color touch screen provides a
control interface and data logging.
More About Dew Point Analysis
A dew point analyzer measures the amount of moisture present in a gas to determine the
theoretical temperature at which the moisture in the gas will condense (the saturation point).
Although dew point is related to the temperature and the pressure of the gas, the dew point of a
gas remains the same regardless of the actual temperature of the gas. Knowing the dew point
of a gas in a heat treating environment can be beneficial in either determining the carbon
potential of the gas, or determining the purity level of the incoming process gases.
The SSi dew point sensor in the 1500 VRSD is considered a high range (“standard”) sensor; it is
designed for gases with temperatures above 0°F (-17.8°C). The sensor uses the relative
humidity (%RH) and the gas temperature to perform a calculation to determine dew point.
On a more technical level, the dew point sensor is a “dielectric ceramic” that varies its electrical
capacitance with changes in relative humidity. The sensor is mounted in a short probe, which is
installed in a T-fitting that allows the sample gas to flow past the sensor. The tip of this probe
contains the dielectric ceramic relative humidity (RH) sensor, as well as a built in temperature
sensor to determine its dry bulb temperature. Information from both of these sensors is used
to compute the resultant dew point.