SR-80 EXTENDED AREA BLACKBODY

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1 SR-80 EXTENDED AREA BLACKBODY PRODUCT TECHNICAL DESCRIPTION Rev. C Prepared by CI Systems, Inc West Agoura Road, Suite 109 Westlake Village, CA Tel: Fax: us@ci-systems.com Web site: Proprietary Information Notice: The information contained in this document is proprietary to CI Systems and may not be reproduced, used or disclosed to others without its prior written consent.

2 TABLE OF CONTENTS TABLE OF CONTENTS II 1. GENERAL Electronic Control Unit Calibration 2 2. SPECIFICATIONS 3 3. OPTIONS Motorized Target Wheel (RAD) Targets Semi Automatic MRTD Test (MRTD-80) High Resolution (HRES) Extended Temperature Range (EXT) Extended Temperature Range II - (EXT-II) SR-80-7A/LT - Low Temperature Absolute Source SR-80-4HT - High Temperature Extended Source SR-80-12HT - High Temperature Extended Source CK-80 - Automatic Calibration Kit 14 i

3 1. GENERAL The SR-80 Infrared Blackbody source consists of an IR source and a multi-option temperature controller. The SR-80 blackbody can be used in either absolute or differential mode. The absolute mode is used for temperature calibration of imaging radiometers, while the differential mode is used for FLIR testing, where the contrast between a target and its background is of interest. The SR-80 Differential Blackbody is used for IR illumination of target patterns at the focal plane of a Test Station Collimator and to perform the MRTD, SiTF, Uniformity, NETD, MTF and FOV tests of the FLIR. The SR-80 Differential Blackbody source consists of an emitter plate, which is electrically heated or cooled with respect to a target sensor, located in the target holder plate. One of the unique features of the SR-80 is its fast response time to temperature changes. The SR-80 responds to a 1 C change within 8-15 seconds, while the response time for a 10 C change is approximately 40 seconds, which significantly reduces testing time. This is due to its very high slew rate (better than 3C/sec) and a sophisticated microprocessor based controller, all packaged in a 19 rack mountable chassis. The temperature range of the SR-80 is from 0 C to 100 C in absolute mode and -20 C to +75 C in differential mode. The temperature uniformity is 0.01 C at a T of ±5 C. The set point and readout resolution are in 0.01 C increments. However, with the HRES option, these are improved to be C resolutions for both set point and display readout. The emissivity of the standard emitter is 0.97±0.02 by using special ultra high emissivity paint, however, with the HEMIS option, the emmisivity is improved. Outstanding among the SR-80 options, the MRTD-80 option enables the operator to continuously change the temperature ramping speed via a hand held joystick. The slew rate is controlled by the length of travel of the joystick (as opposed to a fixed slew rate). With the MRTD-80 option, the MRTD values are automatically registered in the blackbody controller memory. After completion of the MRTD test, the information is transferred to a computer file. The MRTD software produces a plot displaying the achieved and the specified MRTD curves. Stored MRTD information can be analyzed at the convenience of the test engineer. An additional capability for setting and reading a radiometrically compensated temperature difference is a standard feature. As a result of different ambient operating temperatures and effective surface emissivities, changes in radiance difference occur while the temperature difference does not change. Even at a small ambient change of 3 C, the error between the two radiance figures may reach the equivalent of 0.03 C. Since IR sensors sense radiance and not temperature, this discrepancy must be evaluated for each application. A facility for radiometric calibration is available. 1

4 1.1 Electronic Control Unit The blackbody controller is a 19 rack-mountable unit, which is used for controlling the SR-80 temperature and target wheel position. It may be controlled either manually from the front panel via touch keys or from the computer via IEEE-488 (GPIB) communication link. A microprocessor based Temperature Controller maintains an accurate temperature difference ( T) between the emitter and target plates. Its digital display shows the T set-point, the momentary temperature difference and either the absolute emitter or target temperatures (user selectable). The user sets the desired blackbody temperature difference ( T). The temperature controller can control either the differential temperature or the absolute emitter temperature as selected by the user. This sensor provides the reference temperature for the SR-80 differential blackbody, enabling the SR-80 to generate a temperature difference between the target plate (which is assumed to be at ambient temperature at all times with no thermal gradient to the sensor) and the emitter plate which gets heated and cooled to achieve the required differential temperature levels. The SR-80 controller includes NOVRAM that contains the calibration look-up table that compensates for differences of the various characteristics that influence the temperature accuracy. Periodically, the SR-80 has to be recalibrated, and the NOVRAM re-written with the new parameters. 1.2 Calibration Each SR-80 blackbody is individually calibrated with its own temperature controller. During the calibration procedure, the actual emitter temperature is measured and stored into the controller memory. The temperature calibration is performed on both emitter and target sensors, Platinum Resistance Thermometers (PRT s), individually. The difference between them is then controlled, this increases accuracy by eliminating the PRT s nonlinearity. The temperature calibration is traceable to the International Temperature Scale of 1990 (ITS-90) via the National Institute of Standards and Technology (NIST). The recommended recalibration period of the SR80 blackbody is 12 months. A Calibration kit is available from stock for user to facilitate in house calibration (CK-80 option). 2

5 2. SPECIFICATIONS Temperature Range SR-80-4D/A SR-80-7D/A SR-80-12D/A Differential -20 C To +75 C -20 C to +50 C -20 C to +50 C Absolute +5 C To +100 C +5 C to +75 C +5 C to +75 C Specifications for SR-80-4D Model Differential Temperature Accuracy (@25 C ambient temperature) : ±0.1% or ±0.01 C wichever is greater Absolute Temp. Accuracy : ±0.05 C Emissivity Of Emitter : 0.97 ± 0.02 Set-Point & Readout Resolution : 0.01 C (0.001 C optional) Uniformity : ±0.01 C (@ T=±5 C) Short Term Temperature Stability T < 10 C : ± C (1min) 10 C < T < 20 C : ± 0.01 C (10min) 20 C < T < 50 C : ± 0.02 C (10min) 50 C < T < 75 C : ± 0.05 C (10min) Long Term Differential Temperature Stability Per 1C Ambient Change (<2 C/hour) : ±0.002 C Per Year : ±0.04 C Line Voltage Sensitivity (For 10% Voltage Changes) : ±0.01 C Response Times At T < 10 C Including Settling To ±0.02 C 0.1 C Step : 10 Seconds 1 C Step : 15 Seconds 10 C Step : 60 Seconds Temperature Control Unit : 19" 3U Rack Mount. Dimensions (WxDxH) : 400x430x133mm (15.7 x16.9 x5.2 ) Connecting Cable Length : 12 Feet Controlled Temperature Ramping Capability : C/Sec To 0.1 C/Sec Line Voltage : 220 / 115VAC, 50/60 Hz Power Consumption : 400 Watts Max. Operating Temperature : 0 C To 50 C Storage Temperature : -20 C To +70 C 3

6 Emitter Target Holder Heat Sink Fan ` Figure. 1 - SR-80 Differential BB - Schematic Drawing 4

7 Figure. 2 - SR80 - ICD DRAWING Model A B C F G H I J K M SR80-4D/A UNC SR80-7D/A UNC SR80-12D/A UNC * Dimensions in mm 5

8 Figure 3 - SR80-2D/A 6

9 Figure 4 - RAD-6 - Target Wheel Model A B SR80-4D - RAD6 / RAD SR80-7D - RAD6 / RAD * Dimensions in mm 7

10 Figure 5 - SR80-2D + RAD-8 - ICD Drawing 8

11 3. OPTIONS Models SR-80-2D SR-80-4D SR-80-7D SR-80-12D Emitting Surface Size [Inches] 2 Diameter 4 x4 7 x7 12 x12 The Differential blackbodies are identified as D type models, and may be used as Absolute blackbody sources ( A type). 3.1 Motorized Target Wheel (RAD) Motor driven target wheel with a number of interchangeable target patterns. The target wheel is controlled either locally from the blackbody controller front panel, or remotely through the same controller's GPIB communication link. Sliding temperature sensor is located near the active target for accurate temperature difference control. This sensor provides the reference temperature for the SR-80 Differential Blackbody, enabling the SR-80 to generate a temperature difference between the target plate (which is assumed to be at ambient temperature at all times) and the emitter plate which gets heated and cooled to achieve the required differential temperature levels. It may be displaced from that position by commanding the target wheel positioning stage. The target wheel is motor driven and it is activated through the IEEE-488 link. RAD models No. of Target Positions Max. Target Size (Diameter) RAD mm [4.6 ] RAD mm [0.8 ] RAD mm [2 ] * Only for SR-80-2D Targets Targets are made of thin foils (the smaller ones) or cut directly onto the target plates. The target plates are reflective on the side facing the blackbody, so as to avoid heat build-up due to radiation. The other face of the targets (the side facing the UUT) are coated with special, high emissive paint, which is also used for the blackbody emitter, featuring average emissivity (2 to 12 µm) of This ensures that there is no difference between the emissivities of the target and its background. 3.2 Semi Automatic MRTD Test (MRTD-80) Semi-Automatic MRTD feature for faster, more objective and accurate Minimum Resolvable Temperature Difference (MRTD) test and data storage. Includes: Joystick module Software for operating on a PC computer an MRTD curve computation. 9

Motorized target wheel (RAD option) is recommended for optimum utilization of this option. Figure 6 - SR-80 Differential Blackbody with RAD-12 Target Wheel 3.3 High Resolution (HRES) 0.

12 Motorized target wheel (RAD option) is recommended for optimum utilization of this option. Figure 6 - SR-80 Differential Blackbody with RAD-12 Target Wheel 3.3 High Resolution (HRES) C set-point and readout resolution for ±20 C differential temperature range. 3.4 Extended Temperature Range (EXT) SR-80-4D SR-80-7D SR-80-12D Differential Temp. Range : -35 C to +100 C -20 C to +75 C -20 C to +75 C Absolute Temp. Range : -10 C to +125 C 5 C to +100 C 5 C to +100 C 10

13 3.5 Extended Temperature Range II - (EXT-II) This option is available only for SR-80-4D. Specifications: Differential Temperature Range : -20 C To +160 C Absolute Temperature Range : +5 C To +185 C Differential Temperature Accuracy (@25 C ambient temperature) : ±0.1% or ±0.01 C wichever is greater Absolute Temp. Accuracy (@100 C < T < 180 C) : ±0.2 C Short Term Temperature Stability (@100 C < T < 180 C) : ± 0.1 C Emissivity Of Emitter : Power Consumption : 500 Watts Max. 3.6 SR-80-7A/LT - Low Temperature Absolute Source The low temperature blackbody system is composed of a blackbody head and a refrigerated circulator. The refrigerated circulator pumps a cooled fluid into the blackbody heat sink to assist cooling the emitter to the selected temperature. The circulator cools / heats the blackbody s heat sink to a T of 20 C above / under the blackbody temperature set point. The thermo-electric modules control the temperature difference between the heat sink and the emitter, thus providing an accurate emitter temperature control. Specifications: Emitter size : 7 square Absolute Temperature Range : -40 C to +80 C Temperature Accuracy : ±0.05 C Temperature Stability : ±0.01 C Set-Point & Readout Resolution : 0.01 C Emissivity Of Emitter : 0.97 ± 0.02 Refrigerated Circulator : Model - Julabo FP50-MH Temperature Range : -50 C to +200 C Temperature Stability : ±0.01 C Display Resolution : 0.01 C Heater Capacity : Cooling Capacity, Medium Ethanol : C Control Interface : RS232 Dimensions (WxDxH) : 420x490x700 mm Weight : 58kg Line Voltage : 230V/50Hz (115V/60Hz Optional) Safety Class : 2 11

14 3.7 SR-80-4HT - High Temperature Extended Source Specifications : Emitter Size : 4 square Absolute Temperature Range : 50 C to 600 C Temperature Accuracy : ±0.5 C Temperature Stability : ±0.15 C typ. Set-Point & Readout Resolution : 0.1 C Emissivity Of Emitter : Computer Control : IEEE-488 Line Voltage : 115 / 220VAC ; 60/50Hz Figure 7 - SR-80-4HT - ICD drawing 12

15 3.8 SR-80-12HT - High Temperature Extended Source Specifications : Emitter Size : 12 square Absolute Temperature Range : 100 C to 550 C Temperature Accuracy : ±0.5 C Temperature Stability : ±0.5 C typ. Set-Point & Readout Resolution : 0.1 C Emissivity Of Emitter : Computer Control : IEEE-488 Line Voltage : 115 Vac ; 60Hz Power Consumption : 4 KW (Note: all dimensions are in millimeters) Figure 8 - SR-80-12HT - ICD drawing 13

16 3.9 CK-80 - Automatic Calibration Kit The CK - 80 is used for precise calibration of CI Systems Extended Area Blackbodies. It achieves outstanding results by using the most advanced thermally stable electronic circuitry. The temperature of the emitter and target and their differential are digitally displayed. The data is displayed in units of degrees Celsius, Fahrenheit or Kelvin or the PRT resistance value in Ohms. The CK 80 includes a reprogramming software package for CI Systems SR 80 Blackbodies. This enables computer controlled automatic temperature measurement and reprogramming of the Temperature Controller Microprocessor with new calibration data. No Blackbody disassembly is required. The period between Blackbody calibrations recommended for maintaining accuracy is 12 months. The CK 80 includes the following items: Digital thermometer. Two precision temperature sensors (PRT) CI Systems automatic calibration software for the SR-80 CK-80 calibration certificate and complete NIST tractability documentation. 14

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