Brownell has introduced an Electronic Relative Humidity Indicator as an alternative to paper and chemical colour based indicators.
The new Electronic Humidity uses a polymer humidity sensor combined with a thermocouple to provide a digital display reading of relative humidity, ambient temperature and dewpoint. The operating range of the electronic relative humidity indicator is 5 to 80%RH, -20oC to +15oC dewpoint and -20oC to 60oC temperature.
Traditional humidity indicator papers rely on a distinctive colour change usually from blue to pink to signify a dry to wet humidity change. The humidity indication range for paper indicators is from 10% to 70% RH, although this must be specified at an ambient temperature and tolerance range.
The electronic RH indicator removes the uncertainty associated with temperature by converting the readings to dewpoint. Dewpoint is an absolute measure and is not influenced by temperature.
Dewpoint indicates the temperature to which the system or instrument can be cooled before condensation (or frost) will occur. This qualifies dewpoint as a quality control standard for specify an operating performance for systems and instruments.
The Electronic Indicator is mounted in a robust IP67 enclosure with a membrane press switch to activate the three readings in sequence. Optional thread mounting or bulkhead flange fixing is available.
The operational battery life is typically 10 years.