Measurement in dry environments - DM70

DM70 Quick Guide

Document code
M212551EN
Revision
B
Language
English
Product
DM70
Document type
User guide

The following recommendations should be taken into account when measuring in very dry environments:

  • A clean environment is always best for humidity measurements.
  • The number of connections should be minimized to avoid leaks.
  • The flow rate must be adequate.
  • Dead ends must be avoided as they cannot be flushed easily.
  • The tube temperature must never lie under the dew point of the sample gas. This may lead to condensation and false results.
  • The sample tubing should be of as short length as possible. The surface area should be minimized using the narrowest tubing that the flow conditions allow.
  • The surface finish of the pipework is important. Polished or electro-polished steel is recommended for best results.
  • Hygroscopic materials should be avoided in the sampling lines. Use stainless steel membranes instead of rubber membranes.
  • Impermeable materials should be selected to avoid inward diffusion of moisture through the sampling tubes and enclosures. Such impermeable materials are, for example, high-quality stainless steel and metals. Avoid PVC or nylon tubes.