The Gemini R is a blackbody source with which radiation pyrometers, commonly referred to as IR
sensors, can be calibrated. With a temperature range of 30 to 550°C, or 700°C, the
temperature of the cavity can be set with 0.1°C resolution. The temperature of the
furnace is set and indicated on a PID controller. An independent indicator is also provided for
higher accuracy with a standard probe, which indicates the actual radiance temperature.
Temperature variation over a 5-minute period, as viewed on the temperature controller, is
±0.2°C and a radiation thermometer directed into the cavity detects
similar variations.
The Gemini R’s cavity’s size is 2.5″ Ø x 6.3″ deep (65mm x 160mm). Maximum temperature
differences are ±1°C in the range of 100 to 500°C. The Gemini R is capable
of accepting blackbody fixed points to achieve the highest level of a radiation measurement
possible. Typical fixed-point uncertainties are ±0.25°C. Gallium, indium, tin and
zinc cells are available.
Emissivity is greater than 0.995, and a calibration certificate is available for the built-in indicator
and/or supplied probe. The Gemini R can be supplied with RS232 or RS422 communications.
Cal Notepad software now comes standard with the Isotech 976 Gemini R. Cal NotePad Software
automatically logs and displays the temperature of an Isotech calibration bath together with the sensor under test. Cal
Notepad can be used with baths (or indicators) without PC interfaces by the user typing in values from the keyboard.
