Compact Sling Psychrometer Whirling Hygrometer Humidity Brannan - 13/606/2 Whirling Hygrometers, also known as sling psychrometers, employ the "wet" and "dry" bulb principle to determine %RH. They are designed to be rotated, by hand, to provide adequate and consistent ventilation of the bulbs. The Compact Whirling Hygrometer instrument incorporates a 'slide rule' type calculator to determine the % RH. The body of the instrument slides away into the handle providing complete protection when not in use. Fitted with environmentally friendly LO-Tox-filled glass tubers.
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