Cernox® Specifications

Standard curve Not applicable

Recommended excitation1
20 µV (0.1 K to 0.5 K); 63 µV (0.5 K to 1 K);
10 mV or less for T > 1.2 K

Dissipation at recommended excitation Typical 10-5 W at 300 K, 10-7 W at 4.2 K, 10-13 W at 0.3 K (model and temperature dependent)

Thermal response time (typical) BC, BR, BG: 1.5 ms at 4.2 K, 50 ms at 77 K, 135 ms at 273 K; SD: 15 ms at 4.2 K, 0.25 s at 77 K, 0.8 s at 273 K; AA: 0.4 s at 4.2 K, 2 s at 77 K, 1.0 s at 273 K

Use in radiation Recommended for use in radiation environments — for more information click here

Use in magnetic field Recommended for use in magnetic fields at low temperatures. The magneto-resistance is typically negligibly small above 30 K and not significantly affected by orientation relative to the magnetic field — for more information click here

Reproducibility2 ±3 mK at 4.2 K

Soldering standard J-STD-001 Class 2

1 Recommended excitation for T < 1 K based on Lake Shore calibration procedures using an AC resistance bridge — for more information refer to Appendix D and Appendix E

2 Short-term reproducibility data is obtained by subjecting sensor to repeated thermal shocks from 305 K to 4.2 K

Range of use

 Minimum limit3 Maximum limit
Cernox® 0.10 K325 K
Cernox® HT 0.10 K420 K

3 Model dependent

Calibrated accuracy4

 Typical sensor accuracy5Long-term stability6
1.4 K ±5 mK ±3 mK
4.2 K±5 mK±3 mK
10 K±6 mK±6 mK
20 K±9 mK±12 mK
30 K±10 mK±18 mK
50 K±13 mK±30 mK
77 K±16 mK±46 mK
300 K±40 mK±180 mK
400 K±65 mK

4 Bare chip sensors can only be calibrated after attaching gold wire leads – the user must remove the ball bonded leads if they are not desired (the bond pads are large enough for additional bonds)

5 [(Calibration uncertainty)2 + (reproducibility)2]0.5 for more information see Appendices B, D, and E

6 Long-term stability data is obtained by subjecting sensor to 200 thermal shocks from 305 K to 77 K

Temperature response data table (typical)

 CX-1010CX-1030CX-1050
T(K)R8(Ω)dR/dT
(Ω/K)
(T/R)·
(dR/dT)
R(Ω)dR/dT
(Ω/K)
(T/R)·
(dR/dT)
R(Ω)dR/dT
(Ω/K)
(T/R)·
(dR/dT)
4.2277.32-32.209-0.49574.20-97.344-0.713507.2-1120.8-1.34
10187.11-8.063-0.43331.67-19.042-0.571313.5-128.58-0.98
20138.79-3.057-0.44225.19-6.258-0.56692.81-30.871-0.89
30115.38-1.819-0.47179.12-3.453-0.58482.88-14.373-0.89
77.3570.837-0.510-0.56101.16-0.820-0.63205.67-2.412-0.91
30030.392-0.065-0.6541.420-0.088-0.6459.467-0.173-0.87
400 (HT) 34.779-0.050-0.5746.782-0.093-0.79
420 (HT)33.839-0.045-0.5545.030-0.089-0.77

   
 CX-1070CX-1080
T(K)R8(Ω)dR/dT
(Ω/K)
(T/R)·
(dR/dT)
R(Ω)dR/dT
(Ω/K)
(T/R)·
(dR/dT)
4.25979.4-2225.3-1.56
101927.2-214.11-1.11
20938.93-46.553-0.996157.5-480.08-1.56
30629.90-20.613-0.983319.7-165.61-1.50
77.35248.66-3.150-0.98836.52-15.398-1.42
30066.441-0.201-0.91129.39-0.545-1.26
400 (HT) 51.815-0.106-0.8191.463-0.261-1.14
420 (HT)49.819-0.094-0.8086.550-0.231-1.12

8 Cernox sensors do not follow a standard response curve — the listed resistance ranges are typical, but can vary widely; consult Lake Shore to choose a specific range


Physical specifications

 MassLead typeInternal atmosphereSensor materials
Bare chip
(BC), (BG), (BR)
≤3.0 mgBR: none
BG: two 2 mil (44 AWG), bare gold, 25 mm long wires
BC: two 2.5 mil (42 AWG), bare copper, 25 mm long wires
NA Ceramic oxynitride, gold pads and sapphire substrate with Au Pt Mo back (chip in all models)
Hermetic ceramic package
(SD)
≈40 mg2 gold-plated copper VacuumChip mounted on sapphire base with alumina body and lid, Mo/Mn with nickel and gold plating on base and lid, Gold-tin solder as hermetic lid seal, 60/40 SnPb solder used to attach leads
Copper canister package
(AA)
≈390 mg4 phosphor bronze with HML heavy build insulation attached with epoxy strain relief at sensor Helium 4 (4He) is standardChip mounted in gold plated cylindrical copper can


cernoxts_aa_pack
AA package
Wires with the same color code are connected to the same side of the sensor (looking at epoxy seal with leads toward user)

Cernox® calibration ranges

cernox-calibrations

Typical magnetic field-dependent temperature errors7 ΔT/T (%) at B (magnetic induction)

Cernox® 1050
T (K)2.5 T 8 T14 T19 T
21.33.13.95
4.20.1-0.15-0.85-0.8
100.04-0.4-1.1-1.5
200.040.02-0.16-0.2
300.010.040.060.11
770.0020.0220.0620.11
3000.0030.0040.0040.006

7 Excellent for use in magnetic fields, depending on temperature range (>2 K)

Magnetic field dependence data for sample CX RTDs

Magnetic Field Dependence Data

Typical temperature reading errors for operation of CX-1050 sensors in magnetic fields at temperatures from 2.03 K to 286 K. “Low temperature thermometry in high magnetic fields VII. Cernox™ sensors to 32 T,” B. L. Brandt, D. W. Liu and L. G. Rubin; Rev. Sci. Instrum., Vol. 70, No. 1, 1999, pp 104-110.

Neutrons and gamma rays

Neutrons and Gamma Rays

Typical calibration shifts

Typical Calibration Shifts

Typical calibration shift after 200 thermal shocks from 305 K to 77 K for a Model CX-1030 temperature sensor (ΔT = 1 mK at 4.2 K and 10 mK at 100 K).

CX-BR dimensions

CX-SD dimensions

AA dimensions