MICROPROCESSOR PRESSURE AND TEMPERATURE GAUGE

The HD 8804 is a portable instrument with two inputs for measuring pressure and temperature. These two inputs may be connected simultaneosly: two pressure probes, so that the difference between the two values Dp may be calculated as long as the probes have the same fullscale value; two temperature probes, so that the difference between the two values Dt may be calculated; or one pressure probe and one temperature probe may be connected. The HD 8804 enables both variables to be measured with an excellent degree of precision in a range which is substantially limited only by the capacity of the probes. As the probes are interchangeable, the most suitable combination for all applications may be chosen without the need for recalibration. Probes may be connected for measuring absolute pressure (with reference to a vacuum), pressure relative to the atmosphere and differential pressure. For temperature measurements the TP 870 series of temperature probes is used, supplied in the versions for immersion TP 870, for contact measurements TP 870/C, with a penetration point TP 870/P, for measurements in air TP 870/A. The temperature probes have a Pt100 platinum sensor. The liquid or gas under pressure is in contact with the container of AISI 303 stainless steel, the Alumina membrane and the Viton gaskets, so excellent compatibility with most industrial fluids and gases is ensured. The probe contains active electronics, the temperature working range is vast, 0...+80°C, while the thermal drift is compensated. Calibration of the offset, the full scale value, the thermal drift and the automatic indentification of the full-scale value of the probe is accessible and adjustable inside the probe itself.