GLOBE is pleased to announce the addition to the GLOBE protocols of new air temperature measurement techniques using digital max/min thermometers. These instruments offer several advantages over the existing horseshoe-shaped max/min thermometers. They have digital displays that are more easily read by students to the tenth of a degree. They are available with a second temperature sensor used for measuring soil temperature. The digital thermometers contain no mercury, so any concerns along those lines are eliminated.

There are two types of digital thermometers: a multi-day and a single-day. The digital multi-day thermometer stores up to six days of daily maximum and minimum temperature readings in its memory. The use of this thermometer is described in the Digital Multi-Day Max/Min/Current Air and Soil Temperatures Protocol. The digital single-day thermometer is read and reset every day, just like the existing horseshoe-shaped thermometer. The use of this instrument is described in an updated version of the Maximum, Minimum, and Current Temperature Protocol.

Every six months these instruments are calibrated against a calibration thermometer. This calibration process along with other atmosphere measurements provide students with experience reading scales that might otherwise be lacking with use of a digital instrument. The soil sensor attached to the thermometers lets you also collect daily maximum and minimum soil temperatures with minimal added effort. These temperatures are a new measurement in GLOBE. Visualizing the daily records from your digital thermometer provides an excellent means to study how air and soil temperatures change in relation to each other, over the course of a day, a season, and a year.

Remember that when you switch from using a horseshoe-shaped max/min thermometer to a new digital thermometer, you must update your site definition. This way, all data users will know about the change. If you are planning on using both your old and new thermometers for a time, you must define a new site for the new thermometer. GLOBE has no problem with two sites having the same location.

The single-day thermometer is made by HBE International and is called the Digital In/Outdoor Thermometer. The multi-day digital thermometer is made by Taylor Instruments and is model number 1441, and sells for a cost of around $30.00 (US). Please contact the Help Desk if you have any questions about ordering.