Patent ID: 8423311
Filing Date: 2013-04-16
Classification: G01L

Abstract:
1. Method for calibrating measuring cell arrangements, each of which forms an independent apparatus component, wherein each measuring cell arrangement comprises a diaphragm vacuum measuring cell having a measuring connector, the vacuum measuring cell being connected to electronic measuring cell circuitry, which circuitry comprises a measuring cell data memory, a measuring cell control and a measuring cell interface for the exchange of data with peripheral devices, a programmable first heating means encompassing the diaphragm vacuum measuring cell for heating the diaphragm vacuum measuring cell to a constant presettable temperature, the temperature being chosen depending on the process to be measured so as to inhibit condensate depositions within the measuring cell exposed to the process environment when the measuring cell is operated, wherein said first heating means is used additionally for calibrating the measuring cell arrangement, and an insulation jacket encompassing both the first heating means and the diaphragm vacuum measuring cell; wherein the calibration process comprises the following steps: a) connecting at least two of said measuring cell arrangements with a calibration means, with connecting the diaphragm vacuum measuring cell of each measuring cell arrangement measuring connector to a vacuum volume within the calibration means via a measuring connector which forms part of a sealed path between the diaphragm vacuum measuring cell and the vacuum volume, wherein the at least two measuring cell arrangements are each linked to the same vacuum volume, wherein each measuring cell has an outer surface which is not exposed to the vacuum volume, and connecting each the measuring cell interface to a calibration procedure control, wherein the at least two measuring cell arrangements are placed in a single heating chamber within the calibration means, the heating chamber including at least one heating chamber heating means; b) switching on the measuring cell arrangements, and setting each measuring cell arrangement to a first heating temperature using the first heating means of each respective measuring cell arrangement, c) heating the heating chamber in the calibration means using a heating chamber second heating means, wherein the heating chamber heating means is part of the calibration means and is not part of a measuring cell arrangement, d) performing a first calibration step for the measuring cell arrangements by generating at least one preset pressure in the vacuum volume with the simultaneous acquisition of vacuum measuring signals from the measuring cell arrangements and also from at least one reference measuring cell, as well as storage of the vacuum measuring signals in a calibration data memory, e) determining compensation values with a calibration processor from determined differences between vacuum measuring signals of the measuring cell arrangements and of the reference measuring cell, f) gauging the measuring cell arrangements by transmitting the determined compensation values for temperature and pressure from the calibration means to the corresponding measuring cell data memories within the measuring cell arrangements, and g) repeating the steps a) to e) for calibrating the measuring cell arrangements using at least a second heating temperature on each of the measuring cell arrangements.