Oakton WD-37250-20 Acrylic Long Cycle Hygrothermograph, 5.58" Diameter x 13.25" Width x 11.5" Height

The Oakton 37250-20 Hygrothermograph has a selectable one or three-month rotation for humidity and temperature recordings. Hygrothermographs are used to measure and document humidity and temperature over time in computer rooms, greenhouses, food storage rooms, warehouses, museums, and in quality control (QC) laboratories, education and research lab testing environments.

This hygrothermograph features a quartz-controlled drive mechanism for consistent drum rotation throughout battery life, and a battery indicator to prepare the operator. It has an aged bimetallic strip temperature sensor for accurate pressure readings, and a human hair bundle relative humidity (RH) sensor for accuracy. This unit has a flashing LED to indicate drum rotation operation. It has a protective acrylic cover that locks into place for security. Its sturdy base, tinted cover, and carrying handle are lightweight, and corrosion-resistant for a range of use in indoor and sheltered outdoor environments. The hygrothermograph comes with one sheet of pre-attached chart paper, one red cartridge pen, and one blue cartridge pen. The hygrothermograph can be switched to either a one-month or three-month operation by flipping the switch on the accessible top of cylinder drum. The response time is fifteen minutes for 45% of reading.

The 37250-20 hygrothermograph has a relative humidity range of 5-90%, accuracy + or - 3% from 10 to 90 RH; + or - 5% from 5 to 10% RH. It has a human hair bundle sensor, and chart graduations of 1% RH. Temperature range -10 to 50 degrees C/14 to 122 degrees F, accuracy + or - 1 degree C/+ or - 1.8 degrees F. It has a bimetallic temperature strip sensor, and chart graduations of 1 degree C/2 degrees F. Chart rotation is selectable at one-month (38 day maximum) or three months (100 day maximum). Chart paper advances three inches (76.8 mm) per day; paper has two-hour increments. Exposure to RH levels above 90% can cause a decrease of about 7-10% RH in readings over the entire range due to temporary elongation of the hair bundle. When exposed to humidity levels below 80%, hair bundle will return to normal in about three weeks. The meter’s dimensions are 13.3(w) x 11.5(h) x 5.9(l) inches [33.8(w) x 29.2 (h) x 13 (l) cm], and it weighs 9.0 lbs. It is used with one 1.5 volt C battery (not included) for approximately six months of continuous operation.

Hygrothermographs are used to measure temperature and humidity for various applications such as education, general purpose QC labs and research lab testing, and for biological process monitoring.

Oakton Instruments manufactures an array of scientific instruments for research, industrial, and educational uses. Since 1991, Oakton has distributed a wide variety of instruments such as meters, electrodes, and transmitters. Oakton is based in Vernon Hills, IL, and has facilities in Europe, Asia, and China.

What’s in the Box?

• Hygrothermograph
• Blue pen
• Red pen
• Rotation chart paper