AAS-920-614A Datasheet, PDF (2/4 Pages) Amphenol Corporation – Thermometrics Precision, Ultrastable NTC Temperature Standards

Configuration
Temperature standards are enclosed in thin-wall
stainless tubes, welded closed at one end. The shielded
cable is encapsulated into the tube to provide a solid
moisture-proof seal. Full immersion of the metal portion
of the standard is permissible. The calibration data is
given for an immersion depth of 8" on 9" housings, and
4" on 4 1/2" long housings.
Temperature Range
Resistance Vs. Temperature
Characteristic
The nominal resistance values are shown below:
Type
Resistance In Ohms
0°C
25°C
60°C
100°C
“AS” & “S”
14250
5000
1458
–
“AS” & “S”
11400
4000
1166
–
“ES”
28500
10000
2915
925
The Type “S” and Type “AS” are designed for operation
over the range of 0°C to 60°C. The Type “ES” is rated for
0°C to 100°C.
Stability
The stability of each temperature standard is
guaranteed for a period of one year. When properly
used, the following stability ratings apply:
Type “AS” 0.002° C/year
Type “S” 0.005° C/year
Type “ES” 0.005° C/year
Read-Out Devices
Thermometrics’ Temperature Standards are designed
for use with any suitable resistance measuring
instrument. Care must be taken, however, to avoid
excessive self-heating of the thermistor. A power
dissipation of 4 microwatts will result in 0.001°C self-
heat. Self-heat error can be minimized by duplicating
the conditions of calibration which are provided with
each certificate of calibration.
Available Models
Calibration
Precision calibration, traceable to the National Institute
of Standards and Technology, is provided for all
temperature standards. A computer generated table in
increments of 0.01°C is furnished with each calibration
based on the interpolation formula, RT=exp (A₀+ A₁/T
+ A₂/T² + A₃/T³). The constants for the formula are
obtained from a polynomial regression performed on
the calibration data obtained. Over the range of 0°C
to 60°C, calibration is performed at the triple point of
water (0.01°C) and 15°C, 25°C, 30°C, 37°C, 50°C, and
60°C. For the range of 0°C to 100°C, calibrations are
performed at the triple point of water, 25°C, 30°C,
37°C, 60°C, 80°C, and 100°C. Two-wire calibrations are
performed using a wheatstone Bridge calibrated to an
accuracy of better than 0.005%. Four-wire calibrations
are based on a comparison technique using a ratio
bridge having an accuracy of 0.0002%. All resistance
measurements are referenced to standard resistors
calibrated by NIST. All temperature measurements
are made using a standard platinum resistance
thermometer which has been calibrated by NIST.
Three different types are available, each in
four different sizes, to accommodate all standard
requirements:
TYPE “S”, which includes S10, S15, S20, S25, offer
standard 0.005°C/year stability and temperature range
0° to 60° C.
TYPE “AS”, which includes AS110, AS115, AS120, AS125,
offer 0.002°C/yr stability and temperature range 0° to
60° C.
TYPE “ES”, which includes ES210, ES215, ES220, ES225
offer 0.005° C/yr stability and temperature range 0° to
100°C.