Accurate and precise temperature determinations are among several important factors in obtaining reliable thermodynamic data for materials from experiments under extreme pressures and temperatures.
The ability to measure transient temperatures less than 1000K without touching the target remains a challenge.
LLNL researchers have designed and tested performance characteristics for a multichannel pyrometer that works in the NIR from 1200 to 2000 nm. A single datapoint without averaging can be acquired in 14 microseconds (sampling rate of 70,000/s). In conjunction with a diamond anvil cell, the system still works down to about 830K.
It has a relatively small footprint, is portable, only requires low voltage power supplies and can report temperatures down to 800K on the millisecond scale or faster. A single datapoint without averaging can be acquired in 14 microseconds (sampling rate of 70,000/s). In conjunction with a diamond anvil cell the system still works down to about 830K.
Use of photomultiplier tubes requiring power supplies with several hundred volts is avoided. The use of detectors working in the NIR ensures superior performance.
Temperature measurements of very small stationary objects (~ thousands of an inch) on a millisecond scale or faster based on detecting black-body light in the NIR from ~ 1200 to 2000 nm.
The pyrometer has been interfaced several times with a laser heating system. Testing was done in conjunction with another experimental configuration and X-ray diffraction. The system was able to measure temperatures of tunable blackbody sources down to less than 1000K.