Measuring - DM70

With DSC74B, the dew point can be measured at the GIE pressure. If the measurement is done in the GIE pressure, DM70 is able to show the corresponding dew point in the atmospheric pressure.

DSC74B limits the flow rate with a leakage screw. The flow rate is optimized for GIE pressures between 3 ... 10 bar_g, and no external flow meter is needed. The maximum flow can also be increased by removing the leak screw and adjusting the flow manually with the valve.

Remove the leak screw as shown in Figure 1.

Parts per million by volume (ppm_v) and parts per million by weight (ppm_w) are frequently used to indicate humidity. The latter depends on the molecular weight of the gas. For SF₆, the molecular weight is 146.06, and the conversion between ppm_v and ppm_w is the following:

ppm_w = ppm_v / 8.1

DM70 is able to show the ppm_v and ppm_w values for moisture.