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FOLLOWING IS FROM THE USER MANUAL: THE SCITEC MODEL 8201C INFRARED RADIOMETER PROVIDES A MEANS TO MEASURE INFRARED RADIATION (2 TO 12 MICRONS WAVELENGTH) FROM CONTINUOUS WAVE (cw) TO SHORT PLUSEWIDTH SOURCES. THE RADIOMETER ALSO OFFERS A LARGE COLLECTION APERTURE AND A WIDE FIELD-OF-VIEW. THE RADIOMETER HAS TWO BASIC MODES OF OPERATION. ONE, IN PULSED MODE, THE LIQUID NITROGEN COOLED MERCURY-CADMUIM TELLURIDE (MCT) DETECTOR IS CONNECTED A BROADBAND PREAMPLIFIER. THIS PREAMP'S OUTPUT PROVIDES A NET BANDWIDTH OF 1 MHz. SINCE THE FRONT END BANDWIDTH IS LIMITED BY THE DETECTOR A BOOST AMP (HIGH FREQUENCY PEAKING AMP) IS ALSO CONNECTED TO THE OUTPUT OF THE PREAMP. THE OUTPUT OF THE BOOST AMP PERMITS THE TRACKING OF PULSES AS SHORT AS 50 NANOSECONDS WITH GOOD FIDEITY. THE EFFECTIVE OUTPUT OF THE BOOST AMP IS RATED AT 10 MHz. THE SECOND MODE OF OPERATION PERMITS THE MEASURING OF CW SOURCES. THIS IS DONE BY EMPLOYING THE TECHNIQUE OF "SYNCHRONOUS DEMODULATION". IN THIS TECHNIQUE, AN OPTICAL CHOPPER HAS BEEN POSITIONED IN THE RADIOMETER TO MODULATION THE INCOMING SIGINSL TO AFREQUENCY WELL ABOVE THE LOW FREQUENCY CUTOFF OF THE AMPLIFIER. THIS CHOPPER ALSO MODULATES THE BACKGROUND THERMAL RADIATION. HOWEVER, BY EMPLOYING AN AUTO-BALANCE SERVO CIRCUIT THE BACKGROUND SIGNAL IS CONTINUALLY BIASED OUT. THUS, WHEN A TRUE SIGNAL IS DETECTED IT IS GREATLY ENHANCED RELATIVE TO A SIMPLE DIRECT DETECTION SYSTEM. THIS SERVO MAY ALSO BE OVERRIDEN AT ANY TIME, ALLOWING THE USER TO EXERCISE MORE DIRECT CONTROL DURING MEASUREMENT. (Infrared radiometer -scitec MDL8201C & 8616C was posted and is owned by: Agnes Fields) |
agnes_fields@chicagopartsnetwork.com (Agnes Fields) for more information.
