Glass Probe Thermistors

Glass Probe Thermistors

glass thermistors
NTC Interchangeable Chip Thermistor diagram
Sensor Scientific glass probe thermistors are extremely useful in applications that require high stability and ruggedness. The availability of 4 standard outer diameters offers the designer the flexibility to fit the thermistor to the design, rather than compromising the design to accommodate the thermistor. The SP43A style (0.043"/ 1.09mm diameter) provides the small size advantages of the industry-standard large bead (.042" /1.07mm) thermistor without the associated handling problems. Typical applications include fluid flow and fluid level measurement, thermal conductivity measurement, temperature measurement, and temperature compensation.
Glass Probe Thermistors (PDF)
Features:
  • Superior Stability
  • Hermetically Sealed Glass Encapsulation
  • Robust Construction
Options:
  • Custom Lead aLengths
  • Non-Standard Resistance Tolerances
  • Non-Standard Resistance Values
  • Precision Calibration at Multiple Temperatures
  • Custom Value-Added Assembly Options
Specifications:
  • Operating Temperature Range: -40°C to 300°C.
  • Non-Standard Operating Ranges
  • Standard Resistance Tolerance: ±20%
  • Time Constant: 5 To 21 Sec. Typ. In Still Air, Depending On Type
  • Dissipation Constant: 0.4 To 1.0 Mw/°C In Still Air, Depending On Type
MECHANICAL AND THERMAL PROPERTIES
THERMISTOR TYPE   SP43A SP60A SP80A SP100A
GLASS DIMENSIONS
Diameter, nominal (D) inches 0.043 0.060 0.080 0.100
  mm 1.09 1.52 2.03 2.54
Length, nominal (L)
standard inches 0.1 0.25 0.25 0.25
  mm 2.54 6.35 6.35 6.35
standard inches ---- 0.5 0.5 0.5
  mm ---- 12.7 12.7 12.7
custom inches none 0.75 & 1.0 0.75 to 2.0 0.75 to 2.0
  mm none 19 & 25.4 19 to 50.8 19 to 50.8
LEAD WIRES
Material: Tinned Dumet 2          
Diameter, nominal (d) inches 0.008 0.008 0.0126 0.0126
  mm 0.20 0.20 0.32 0.32
Length, nominal (l) inches 1.5 - 2.0 1.5 - 2.0 1.5 - 2.0 1.5 - 2.0
  mm 38 - 51 38 - 51 51 51
THERMAL PROPERTIES
Time constant, still air sec. 5 10 15 21
Dissipation constant, still air mW/°C 0.4 0.7 0.8 1
 
Note 2: Bare (not tinned) Dumet leads are available as an option

PART NUMBER SPECIFICATION:

To specify a part number, the following sequence should be used:

SP80A103201/2 specifies a glass probe thermistor, .080" (2.03mm) diameter, 10000 ohms at 25 Deg. C., with a resistance tolerance of ±20%, and nominal length of ½" (12.7mm) 
# SP80A103201/2 indicates glass probe thermistor 
# SP80A103201/2 indicates nominal diameter 43A = 0.043" (1.09mm) 80A = 0.080" (2.03mm) 60A = 0.060" (1.52mm) 100A = 0.100" (2.54mm) 
# SP80A103201/2 indicates zero power resistance at 25°C. The first two digits indicate significant figures, and the last digit indicates the number of zeros following the significant figures. In this example, "103" represents 10000 ohms. 
# SP80A103201/2 indicates the resistance tolerance at 25°C, expressed in ±%. In this example, ±20" indicates the standard tolerance of ±20%. Other typical tolerances include ±1%, 2%, 5%, 10%, 15%, 20%, and 30%. 
# SP80A103201/2 indicates the nominal body length. 1/4 = 0.25" (6.4mm) 1/2 = 0.50" (12.7mm) 1/1 = 1.00" (25.6mm) 2/1 = 2.00" (51.2mm)

(Note: The SP43A is available only in a 0.1" (2.5mm) length. The length term is omitted in the SP43A part number)

Resistance vs Ratio Table

R 25 /R 125 Ratio α %/Deg. C Beta 25-125
Deg. Kelvin		 Available Nominal Resistance
at 25 Deg. C.ohms
11.89 -3.28 2940 100-500 1
15.07 -3.54 3220 500-1500
19.80 -3.88 3550 1500-3500
22.36 -4.04 3690 3500-7500
29.40 -4.40 4015 7500-28000
29.88 -4.42 4035 28000-42000
31.54 -4.49 4100 42000-80000
37.92 -4.67 4315 80000-175000
38.62 -4.72 4340 175000-375000
48.05 -5.00 4600 375000-750000
54.28 -5.15 4740 750000-1250000
Note 1: Minimum available nominal resistance is 100 ohms for SP43A and SP60A types.
To specify desired resistance tolerances, substitute the required tolerance for '*' in the part number. For example, for a 5% tolerance W502C* part, the complete part number would be W502C5.
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