Model 303B Moisture Analyzer



The Model 303B offers a simple solution to the problem of measuring the moisture content of gas streams. Using an electrolytic (P2O5) sensor, the Model 303B can be used to monitor nearly all gases. It is compact, lightweight, and suitable for both portable use and permanent installation in Class I Div. 2 areas. With the optional carrying bag and lightweight design, the 303B is truly portable.

Every 303B is equipped with the following:

  • digital display
  • rugged moisture cell
  • bypass flowmeter
  • 4 to 20 mA output
  • internal battery and recharging system
  • AC and 12VDC power inputs


The 303B is designed to measure moisture content in gases such as air, nitrogen, argon, natural gas, and others with comparable characteristics. Typical applications are:

  • Monitoring natural gas pipelines and gas treatment processes
  • Monitoring air humidity in dry boxes
  • Continuous monitoring of atmospheres in simulated space chambers
  • Sensing elements in humidity control systems
  • Monitoring inert protective atmospheres in brazing or sintering furnaces
  • Monitoring moisture in many fluorocarbon gases
  • Constant measurement of batch and continuous driers to assure quality control without the expense of overdrying
  • Monitoring anhydrous batch chemical processes at startup
  • Quality control of transistor and diode backfill gas
  • Instrument air systems
  • Cryogenic processes
  • Radar waveguides