Temperature Stabilization Requirements for Unchopped Thermal Detectors
The temperature stabilization requirements of unchopped thermistor bolometers and thermopile detectors are analyzed.
thermistor↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The testing and calibration of detectors used in flight
Testing and calibration of thermopile with quartz- iodine lamps and with black body
RADIATION DETECTOR↗
An intensity and uniformity monitor for solar simulators.
Intensity and uniformity monitor for solar simulators using thermopile as detector
MONITOR↗
Differential temperature transducer Patent
Differential thermopile for measuring cooling water temperature rise
Wald, D.↗
Horizon sensor with a plurality of fixedly positioned radiation compensated radiation sensitive detectors Patent
Horizon sensor design with digital sampling of spaced radiation-compensated thermopile infrared detectors
Mclauchlan, J. M.↗
Differential input preamplifier
Preamplifier chops and amplifies very low level output of thermopile infrared detectors that will be used to measure thermal energy flux of Jupiter and its departure from a blackbody spectrum. Output signal has negligible phase shift. AC signal is RC-coupled to input stage of other amplifiers.
Callaway, P. W.↗
The repulsive 1 Sigma g/+/ He2 potential obtained from total cross sections
An improved apparatus for obtaining short-range molecular potentials is described. The setup is a refined version of that used by Jordan-Amdur and by Leonas. The ion source is provided with a mass analyzing magnet, the capacitance manometer in the scattering cell is calibrated with a McCleod gauge, and the detection unit substitutes a Channeltron multiplier for the thermopile. The measured ground-state He-He potential for radii between 0.49 and 1.56 A is approximately V(r) = 215 x exp(-3.95r) eV, which is 25% higher than the earlier experiments. The result is supported by molecular orbital and statistical model calculations.
Foreman, P. B.↗
Earth radiation budget measurement from a spinning satellite: Conceptual design of detectors
The conceptual design, sensor characteristics, sensor performance and accuracy, and spacecraft and orbital requirements for a spinning wide-field-of-view earth energy budget detector were investigated. The scientific requirements for measurement of the earth's radiative energy budget are presented. Other topics discussed include the observing system concept, solar constant radiometer design, plane flux wide FOV sensor design, fast active cavity theory, fast active cavity design and error analysis, thermopile detectors as an alternative, pre-flight and in-flight calibration plane, system error summary, and interface requirements.
Sromovsky, L. A.↗
Infrared radiometer for the Pioneer 10 and 11 missions to Jupiter
Pioneer 10 has successfully encountered Jupiter and several of its satellites. The two-channel infrared radiometer used to obtain data relating to thermal properties of the planet and its atmosphere is described. The instrument features a body-fixed, 7.62-cm-diam aperture Cassegrainian telescope with restrahlen filters defining the 14- to 25-micron and 30- to 56-micron bands. Detectors are 88-junction evaporated thin-film thermopiles. Stringent weight constraints of 2 kg dictated all-beryllium construction. Power consumption was 1.2 W.
Bender, M. L.↗
Collection efficiency measurements for solar cell research
A system was established for measuring absolute, spectral collection efficiency that is well suited to solar cell research and development. Determination of spectral collection efficiency involves measurements of the incident photon intensity, the device reflection coefficient, and the cell short circuit current. A monochromatic photon flux is obtained with a high intensity Bausch and Lomb monochromator, and an Epply thermopile detector is used to measure incident intensity. Normal incidence reflectivity measurements are achieved with a prism type beam splitter. The experimental approach is discussed, measurements of the reflectivity of evaporated silver films are considered. Collection efficiency measurements of silicon solar cells are presented, and collection efficiency studies of Cu20 solar cells are discussed.
Hampton, H. L.↗
The self-calibrating sensor of the Eclectic Satellite Pyrheliometer /ESP/ program
A self-calibrating thermopile sensor having a cavity type receiver is described. Its incorporation into pyrheliometric instrumentation, including the electronics and control, is also discussed. Completed devices are capable of solar irradiance measurements with an accuracy to within 0.5% and can detect solar variability to a level approaching 0.001% in space.
Hickey, J. R.↗
Viking infrared thermal mapper
The infrared thermal mapper (IRTM) was designed to measure the emitted and reflected radiance of Mars. Carried by the Viking Orbiter, the IRTM contains four small Cassegrainian telescopes which each image the same, seven circular areas. There is a total of twenty-eight channels in four surface and one atmospheric thermal bands from 6 to 30 microns and a broad solar reflectance band. All channels are sampled simultaneously, using the spacecraft scanning capability to map the radiance over small and large areas of the planet. All channels use thermopile detectors; spectral passbands are determined by a combination of interference filters, detector lense materials, antireflection coatings, and restrahlen optics.
Chase, S. C., Jr.↗
The application of solar thermoelectric generators in near-sun missions
Future planetary near-sun missions, such as those studied for low-altitude Mercury Orbiters, introduce challenges in the selection of appropriate power sources. Study results have shown that conventional silicon solar array technology is not adequate to produce power because of expected temperatures which range from -90 C to +285 C in about 40 to 50 minutes for 16 sun eclipses/day. The solar thermoelectric generator (STG), which requires relatively high temperatures, is being considered as a replacement power source. The complete STG consists of a solar concentrator and multiple thermopiles, each containing numerous thermocouples and thermal insulation material. Articulation of the STG design configurations is required at 0.45 AU to acquire maximum incident radiation and at 0.3 AU to reduce the higher incident radiation. STG thermal input to the spacecraft as it orbits Mercury (including sun eclipses) is insignificant.
Raag, V.↗
Performance analysis of a filtered wide field-of-view radiometer for earth radiation budget measurements
The proposed Earth Radiation Budget Satellite System (ERBSS) of the 1980's will include a wide field-of-view (WFOV) fixed axes earth radiator discriminator consisting of a shortwave channel and a total (unfiltered) channel. The broadband spectral isolation required for the shortwave channel is achieved by use of a hemispherical fused silica (Suprasil W) dome filter placed in front of a wire wound thermopile radiation detector. A description is presented of the thermal response of the single-fused silica dome filter in the ERBSS WFOV shortwave channel conceptual design and the impact of that response on the channel measurement. Results from design definition and performance analysis studies are included. Problems associated with achieving the desired levels of confidence in a high accuracy filtered, WFOV radiometer are discussed. Design approaches, ground calibration, and data reduction techniques which minimize measurement uncertainties are explained.
Cooper, J. E.↗
Solar thermoelectric power generation for Mercury orbiter missions
Mercury orbiter mission study results have shown that conventional silicon solar cell array technology is not adequate to produce power because of expected temperatures which range from -90 C to +285 C in about 50 minutes for 16 sun eclipses/day. The solar thermoelectric generator (STG), which requires relatively high temperatures, is being developed as a replacement power source. Several thermoelectric technologies (i.e., lead telluride alloys, bismuth telluride, selenide, and silicon-germanium alloys have been examined for their suitability. Solar concentrator configurations (i.e., flat plate, Fresnel lens, mini-cone, and Cassegrain types) were also studied as candidates for increasing incident radiation during Mercury orbital operations. Detailed results are presented, and show that an STG design based on the use of silicon-germanium alloy thermoelectric material and using high-voltage thermopiles with individual miniconical concentrators presents the optimum combination of technology and configuration for minimizing power source mass.
Swerdling, M.↗
Nimbus-6 and -7 Earth Radiation Budget (ERB) sensor details and component tests
Construction details and operating characteristics are described for the thermopile (used in the solar and fixed-Earth channels) and the pyroelectric detector (used in the Earth-scanning channels) carried on the Nimbus 6 and the Nimbus 7 satellites for gathering Earth radiation budget data. Properties of the black coating for the detectors, and sensor testing and calibration are discussed.
Soule, H. V.↗
Computer modeling of thermoelectric generator performance
Features of the DEGRA 2 computer code for simulating the operations of a spacecraft thermoelectric generator are described. The code models the physical processes occurring during operation. Input variables include the thermoelectric couple geometry and composition, the thermoelectric materials' properties, interfaces and insulation in the thermopile, the heat source characteristics, mission trajectory, and generator electrical requirements. Time steps can be specified and sublimation of the leg and hot shoe is accounted for, as are shorts between legs. Calculations are performed for conduction, Peltier, Thomson, and Joule heating, the cold junction can be adjusted for solar radition, and the legs of the thermoelectric couple are segmented to enhance the approximation accuracy. A trial run covering 18 couple modules yielded data with 0.3% accuracy with regard to test data. The model has been successful with selenide materials, SiGe, and SiN4, with output of all critical operational variables.
Chmielewski, A. B.↗
Ten Thousand Solar Constants Radiometer
"Radiometer for Accurate (+ or - 1%) Measurement of Solar Irradiances Equal to 10,000 Solar Constants," gives additional information on radiometer described elsewhere. Self-calibrating, water-cooled, thermopile radiometer measures irradiance produced in solar image formed by parabolic reflector or by multiple-mirror solar installation.
Kendall, J. M., Sr.↗