Friday, July 09, 2010

Super-Thermometers Calibrate Thermistors And SPRTs

Electronic test and measurement specialist Fluke has introduced the 1594A/1595A super-thermometers from Hart Scientific for the calibration of SPRTs, PRTs and thermistors. The Fluke 1594A and 1595A super-thermometers are accurate enough for the primary lab, providing accuracy to 0.06ppm (0.000015C), and economical enough for the secondary lab. Fluke said metrologists can feel confident that every measurement made with the super-thermometer falls within expected limits, easy verifiable at any time.

The 1594A and 1595A feature patent-pending ratio self-calibration that enables users to test the accuracy or calibrate the resistance ratio linearity of the super-thermometer's measurement circuit without requiring any external devices or special training. Metrologists can verify accuracy and performance automatically in about 30mins at the touch of a button. Although unlikely, measurement circuit defects would be detected and reported automatically. Users can also calibrate the super-thermometer's internal reference resistors using the resistance calibration function and an external standard resistor.

The super-thermometer assists with the calibration through an easy-to-use setup utility. Once the calibration is complete, the super-thermometer reports the results to the display and provides the option to write the results to a USB memory device. Users can also choose whether or not to adjust the calibration parameters of the internal reference resistor by pressing the password-protected adjust resistor function key. Measurement noise is caused by electrical noise and other random errors that can negatively influence measurement accuracy. Patent-pending designs incorporated into the super-thermometer reduce measurement noise and interference to levels that Fluke claimed are unprecedented for a digital thermometry bridge.

In a typical temperature calibration application, uncertainty due to measurement noise is as low as 0.00002C. Super-thermometers offer speeds as fast as one second per measurement (full accuracy with a two-second sample rate). This means users can complete tests in less time, track temperature changes more accurately and evaluate thermal response in sensors. When measuring fixed-point temperatures that require the highest levels of accuracy and lowest levels of noise, users have complete control to change the measurement speed to meet their requirements.

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