The principle of a dry-block calibrator is basically very simple: 'Heating up a metal block and keeping the temperature stable.' This basic design gives the user a lot of advantages compared to the more traditional liquid baths.
RELIABLE TEMPERATURE SOURCE - MOST IMPORTANT
A good user interface and integrated solutions offer you timesavings and easy handling of even difficult calibration jobs. But the quality of your temperature calibration measurements still depends on the quality of the temperature source.
The temperature block must be very stable and at the same time have a good temperature homogeneity. This is very important because the sensors-under-test may have different measurement zones. As the sensor-under-test will also act as a thermal load in the block during the calibration, it is important that the block keeps the good homogeneity even with multiple numbers of probes and with large probes.
The new dual-zone design of the heating block is the most innovative step taken to solve the thermal problems mentioned above. AMETEK JOFRA has developed two different versions of the dual-zone principle - the ACTIVE-CONTROL and the CENTRAL-CONTROL versions. Both versions eliminate the need for insulation of the sensors-under-test and make it possible to calibrate liquid filled and other mechanical sensors.
STATE-OF-THE-ART WELL DESIGN - OPTIMIZED FOR ACCURACY
Dual-Zone Heating Block: Active-Control
The heating block is constructed in two zones, with SEPARATE active-control of each zone. The homogeneity in the lower part of the block is close to that of a laboratory liquid bath. The lower zone controls the calibration temperature. The upper zone compensates for heat loss through the sensor-under-test and from the top of the block, and ensures a good homogeneity independent of the load.
The active-control dual-zone heating blocks are used in the AMETEK JOFRA temperature calibrators ATC-156, ATC-157, ATC-320 and ATC-650.
AMETEK JOFRA is a world leading manufacturer of calibration equipment for temperature, pressure and process signal. A comprehensive technical section covering a range of calibration issues can be found at www.jofra.com/sw29.asp