Shows Relative Humidity and Temperature
in both Fahrenheit and Centigrade at a glance
In Germany, Lufft has been making fine meteorological instruments for over 100 years. Abbeon has been offering their high quality instruments here in the U.S. for over forty years. The Lufft instruments shown here have white faceplates with black lettering. (Red lettering is added for Celsius scales when they are included).
The humidity is sensed by a Durotherm element that is a synthetic hygroscopic fiber that expands and contracts in response to the moisture in the air. The thermometers are actuated by bimetallic springs which transmit changes in temperature through expansion and contraction. Accuracy for these instruments are ±2.5% + 1 scale division for the relative humidity and ±1°C (0 - 40° C) + 1 scale graduation for the temperature.
The Abbeon Certified Hygrometer Model HTAB-176 is certified to be accurate within ± 2.5% RH + 1 scale division. The dial indicates the complete range of 0 to 100% relative humidity.
Each instrument has been tested for accuracy at 3 points on the scale for high, medium and low readings. The calibration and certification are done under ISO-9001 control. The bi-metallic thermometer on the model HTAB-176 is accurate to ±1% of scale with a range of -20 to 100° Centigrade and 0 to 210° Fahrenheit.
Graduations are 1° for Centigrade, 2° Fahrenheit and 1% RH.
This is the only humidity indicator that we know of that has a 1-year guarantee and a 5-year warranty. Some of our humidity indicators working on the same principle as this instrument have been in use for over 10 years and are giving satisfactory service day after day, month after month, and year after year. Both the humidity and temperature are directly read without any calculations whatsoever.
Solid 6-inch overall brass case drilled for wall mounting. Shipping weight: 3 pounds. Color differentiated 5-inch dial with black letters and numbers and a red pointer. Because these are mechanical instruments, they will not hold the ± 2.5% accuracy on the far ends of the scale (below 20% and above 80%).