The Taylor 5522S Mason Hygrometer (or Mason's Hygrometer) is a wet and dry bulb Fahrenheit thermometer pair that tells you the temperature and relative humidity in your home or virtually any other indoor or sheltered location where the temperature remains above 32°F. The humidity indication is based on the difference between the wet and dry bulb temperatures, and you obtain this value from tables in the instruction manual. This hygrometer is environmentally safe because its thermometers are spirit-filled and thus contain no mercury. The 5522S mounts on a wall or other vertical surface by means of a screw, nail, or hook.

The 5522S is easy to use and maintain. Here's all you need to do. Fill the reservoir (sometimes called a cistern) with water. Distilled water is highly recommended to prevent mineral buildup on the reservoir and wick). Then insert the wick into the reservoir, hang the unit, and wait for the wet bulb temperature to stabilize.  If there's not much air movement, aiming a fan at the wick will result in a more accurate humidity reading. When the wet bulb temperature stabilizes, go to the Fahrenheit tables in the instruction manual to find the relative humidity. Two types of tables are provided. With the first type, you simply cross-reference the wet bulb temperature with that of the dry bulb. With the second table type, you determine the thermometer depression (dry bulb temperature minus wet bulb temperature) and then cross-reference the depression with the dry bulb temperature. Be sure to clean and refill the 5522S's reservoir and clean or replace the wick when these tasks become necessary.

The instruction manual for this product is generic. It covers not only the 5522S but also those 5522-series thermometers that contain mercury, and it also covers Taylor sling psychrometers. You will find manual to be very informative. You should be aware that the tables in the manual are computed for a barometric pressure of 29.00 inches of mercury. At lower pressures (higher altitudes), the true relative humidity will be slightly higher that that indicated in the tables. This and more useful information is provided in the Foreword and instructions, so be sure to read these before using the 5522S.

The two thermometers on the 5522S are physically identical and easy to read with black numbers on a white background. The thermometer scales read from 10°F to 130°F with markers at 2° increments. The body of the 5522S is dark brown plastic with markings to resemble mahogany wood. This instrument is 4-1/4 inches wide by 8-3/4 inches high.

Like all thermometers, the Taylor 5522S non-mercury wet/dry bulb hygrometer is not to be mounted in direct sunlight or where there is a great deal of reflected light.

In addition to the instruction manual with relative humidity tables, the 5522S comes with a spare wick and a manufacturer's 1-year limited warranty.

Features:

• For use indoors and in sheltered locations above 32°F.
• Functionally designed and easy to use and maintain.
• Wet and dry bulb thermometers indicate temperatures in °F in easy-to-read black-on-white numbers.
• Two types of relative humidity tables included in instruction manual:
  • First table type cross-references dry bulb temperature with wet bulb temperature.
  • Second table type cross-references thermometer depression (dry bulb temperature minus wet bulb temperature) with dry bulb temperature.
• Environmentally safe (red spirit-filled thermometers, no mercury).
• No batteries required.

Specifications:

• Thermometer measuring range: 10°F to +130°F (scales are in 2° increments)
• Dimensions:
  4-1/4 inches (108 mm) wide
  8-3/4 inches (222 mm) high
  1-1/4 inches (32 mm) deep