Version 1.0 ©Copyright 2014, Ambient LLC. All Rights Reserved. Page 2
1. Introduction
Thank you for your purchase of the Ambient Weather WS-208TBH 9" Brushed Aluminum Traditional
Thermometer with Barometer and Humidity, Metallic Radiant Blue The following is a guide for
preparation, care and operation of your traditional weather station.
2. Care and Cleaning
Avoid use of harsh household cleaners and coarse paper towels, which can damage the lacquer coating
or scratch the bezel or lens. Fingerprints and dirt may be removed the lenses and bezels with a soft
cloth lightly dampened with a mixture of water and mild dishwashing liquid. Be sure to dry the lens
and bezel with a soft cloth after cleaning.
Do not install the weather station outside. The weather station is intended for indoor use only.
3. Hygrometer (Humidity Meter)
3.1 How the hygrometer works
The hygrometer measures the indoor relative humidity. The sensor measures the air moisture by a
sensitive mechanical coil spring that is bonded with a moisture absorbent material.
Hygrometers register the percentage of water vapor present in the air, compared to the maximum
amount that can be present at a given temperature.
The coils in hygrometers respond slowly and while humidity levels change abruptly, it can take an
hour or more for the meter to reach an accurate reading. Remember that the hygrometer is reading
indoor humidity, and is vastly different than outdoor humidity, as reported by the National Weather
Service.
It is not uncommon to have low humidity reading during cold weather when indoor air is heater. Air
conditioning also removes moisture from the air. The optimum levels are 45% to 50% during
heating and cooling seasons. Low humidity can cause health problems and can be hard on wood
furnishings. High humidity can cause mold or mildew to grow.
3.2 Hygrometer Accuracy
Humidity measurement is among the more difficult problems in basic meteorology. Accuracy is
difficult to achieve and are subject to drift, so need regular recalibration.
A further difficulty is that most hygrometers sense relative humidity rather than the absolute amount
of water present, but relative humidity is a function of both temperature and absolute moisture content,
so small temperature variations within the air in a test chamber will translate into relative humidity
variations.
