Proceedings Article | 30 May 1995
KEYWORDS: Modulation transfer functions, Temperature metrology, Lithium, Sensors, Cameras, Digital filtering, Analog electronics, Digital electronics, Measurement devices, Optical arrays
Uncooled pyroelectric arrays can be advantageously used for contactless measurements of one- and two-dimensional temperature fields. Satisfying values of noise equivalent power NEP, modulation transfer function MTF and long term stability of responsivity, respectively, are necessary for these applications. Linear pyroelectric arrays developed for those purposes are described. The pyroelectric chip based on lithium tantalate contains 128 sensitive elements (element size 90 X 100 micrometers 2 with 100 micrometers pitch). A CMOS read-out circuit (low noise preamplifiers, S&H-stages, analog switching structures with digital components, output-amplifier) is specially designed. Pyroelectric chip, read-out circuit, and a PTAT temperature sensor chip, respectively, are mounted in a metal hermetic package with 8...12 micrometers germanium window. Measured NEP values reach 5 nW at a chopping frequency of 128 Hz. The modulation transfer function MTF (128 Hz, 3 lp/mm) measured is typically 60%. Devices for the measurement of temperature distributions based on linear arrays described contain the uncooled array, infrared optics, chopper, control electronics, analog to digital converter, and a comfortable digital processing unit for multi point pattern correction, accumulation, digital filtering and so on. The measuring range of such PYROLINE systems reaches from 0...80 degree(s)C, 50...300 degree(s)C, 200...700 degree(s)C (1500 degree(s)C), respectively.
