Temperature probe specifications

These probes are not designed to be intrinsically safe. It is the user's responsibility to operate these probes safely in explosive environments.

NOTE: A drawback of installing sensors in a stainless-steel probe is the reduction of the thermal connection between the sensor and the temperature of interest. Temperatures below 20 K become difficult to read accurately depending on probe configuration. As a result, these probes are not recommended for temperatures below 20 K. For these temperatures, a Cernox or diode temperature sensor should be mounted directly to a protected surface closest to the temperature of interest, with the wires sufficiently thermally anchored to allow the sensor to read the temperature of interest as accurately as possible.

Probe construction

Stem

Material: 316 stainless steel (non-magnetic)1

 Wall thicknessMaximum length
1/4 in stem0.028 in ±0.003 in28 in2
1/8 in stem0.010 in ±0.001 in20 in

1Not suitable for direct immersion in liquid oxygen or hydrogen environments.
2Lengths may be possible depending on the overall configuration. Please contact Lake Shore to discuss.

Internal components

Internal atmosphere: Air
Internal atmosphere pressure: 98 kPa (14.2 psia)
Internal sensor wire: Quad-Twist™ 4-lead 36 AWG phosphor bronze wire with polyimide insulation
Maximum rated temperature: 378 K

Probe mount

Swagelok® fittings

Swagelok fitting
 1/4 in probe1/8 in probe
Swagelok® part number:SS-400-1-4BTSS-200-1-2BT
Material316 stainless steel
Thread0.25 in NPT male0.125 in NPT male
A1.59 in1.5 in
B0.25 in0.125 in

CF flange

CF flange

Material: 304L stainless steel
Flange size: 113 in (DN16)
Vacuum rating: 1 × 10-13 Torr (<1.3 × 10-13 mbar)*
*Requires the use of appropriate bolts, gasket, and mating surface.

Connectors

BNC connector

Standard male BNC connector. When ordering with 4-lead wire, two separate BNC connectors will be provided to maintain the 4-lead measurement.

Configuration:

 BNC 1BNC 2
 Center pinShieldCenter pinShield
2-lead cableI/V+ (anode)I/V- (cathode)
4-lead cableI+I-V+V-

10-pin Detoronics® connector

The Detoronics connector is o-ring sealed to the temperature probe.

Note: This connector is mounted directly to the probe, meaning that no external cable can be selected with this option. It also eliminates the CF flange probe mount option.

10-pin Detoronics connectorDT02H—flange mount connectors (MIL-STD-3112H type)

General specifications
Air leakage: 1 × 10-6 cm3/s at 15 psi
Insulation resistance: 5,000 MΩ at 500 VDC
Operating temperature: -55 °C to +125 °C (-67 °F to +257 °F)

Finish is tin-plated shell and pins

Materials
Shell, bayonet, and flange: Carbon steel
Pins: 52 nickel alloy
Insulator: Glass

25-pin D-sub connector

25-pin D-sub connector

The 25-pin D-sub is required to connect directly to particular Lake Shore temperature monitors.

Supported instruments:

  • Model 211
  • Model 218

6-pin DIN connector

6-pin DIN connector

The 6-pin DIN is required to connect directly to particular Lake Shore temperature controllers and monitors.

Supported current instruments:

  • Model 350
  • Model 336
  • Model 335
  • Model 224

Supported discontinued instruments:

  • Model 340
  • Model 331/332
  • Model 330 (diodes only)
  • Model 321 (silicon diodes only)

Connector configurations

Connector typeI+V+I-V-Shield*
2-lead BNC
(1 connector)
Center pinOuter cup (shield)Not connected
4-lead BNC
(2 connectors)
Center pin of ‘I’ BNCCenter pin of ‘V’ BNCOuter cup of ‘I’ BNCOuter cup of ‘V’ BNCNot connected
10-pin probe-mounted Detoronics connector®Pin APin CPin BPin DNA
6-pin DINPin 5Pin 4Pin 1Pin 2Pin 6
25-pin D-subPin 3Pin 4Pin 15Pin 16Pin 2

*Shield connection is only used in conjunction with external cable choices that include a braided shield (Cryocable™ and instrument cable)

Wire

Instrument cable

Robust 4-lead cable best for wiring to instrument where both the wire and instrument are at room temperature. The 30 AWG signal wires make these wires easier to work with than traditional cryogenic wire.

Instrument cable


Rated temperature: -20 °C to 80 °C
Thermal conductivity (300 K): 400 W/(m·K)
Resistance (300 K): 0.32 Ω/m
Supported sensor types: Cernox® RTD, silicon diode, GaAlAs diode, platinum RTD

Cryogenic wire

Phosphor-bronze wire combinations that limit heat transfer into the temperature probe and are themselves rated for use in cryogenic environments.

 Quad-Twist™ 36 AWG*Quad-Twist™ 32 AWGQuad-Lead™ 32 AWGDuo-Twist™ 32 AWG
Configuration4-lead2-lead
WirePhosphor bronze
Gauge36 AWG32 AWG
InsulationFormvarPolyimide
StructureTwo twisted pairsFour wires formed into a ribbon using Bond Coat 999 bonding filmOne twisted pair
Thermal conductivity (300 K)48 W/(m·K)
Resistance (300 K)10.3 Ω/m4.02 Ω/m
Supported sensorsCernox® RTD, silicon diode, GaAlAs diode, platinum RTDDiodes only

*Also used for internal probe wiring. Ordering this cable will result in a continuous length of wire from the sensor through to the outside environment.

SS (stainless steel) coaxial cable

2-lead cabling solution that is extremely robust and limits heat transfer into the probe. Due to the 2-lead configuration, this cable is only compatible with diode sensors and will cause a predictable (potentially insignificant) offset in any temperature readings.

Stainless steel coaxial cable

Electrical properties
Resistance—center conductor at 295 K (22 °C): 23.62 Ω/m (7.2 Ω/ft)
Resistance—shield at 295 K (22 °C): 3.61 Ω/m (1.1 Ω/ft)
Insulation temperature range: 10 mK to 473 K
Supported sensor types: Silicon diode, GaAlAs diode

Cryocable™

A robust, 4-wire cable for use in cryogenic environments to room temperature for ultimate thermal isolation from external heat sources. This cable is designed around 32 AWG (203 µm) diameter superconductive wires consisting of a NbTi core (128 µm diameter) and a Cu-10% Ni jacket. The wire is LTS, requiring very low temperatures for it to become superconducting.

CryoCable

Minimum bend radius: 15 mm (0.6 in)
Superconducting critical temperature: 9.8 K
Superconducting critical magnetic field: 10 T
Supported sensor types: Cernox® RTD, silicon diode, GaAlAs diode, platinum RTD

Magnetic fieldCritical current (per wire)
3 T35 A
5 T25 A
7 T15 A
9 T6 A

 Temperature (K)
295774.2
Wire resistance (Ω/m)9.28.40*
Overbraid resistance (Ω/m)0.900.640.62

Thermal conductivity—entire cable assembly (W/(m·K))

7.62.80.17

*Superconducting

Wire configurations

Wire typeI+V+I-V-Shield
Instrument cableBlackYellowRedBlueCopper braid
Quad-Twist™ 36 AWGGreen (from red/green pair)Green (from clear/green pair)RedClearNone
Quad-Twist™ 32 AWGRedBlackGreenClearNone
Quad-Lead™ 32 AWGClearBlackRedGreenNone
Duo-Twist™ 32 AWGClearGreenNone
Stainless steel coaxialCenter conductorShieldNone
Cryocable™BlackYellowWhiteGreenStainless steel braid
Wire configuration diagram

Temperature sensors

See individual sensor pages for specifications:
Cernox
DT-670
Platinum

Sensor typeInstalled sensor package
Cernox®SD
DT-670SD
PlatinumStandard PT-100 Series packages

All temperature sensor calibrations are performed before the device is installed into the probe. At this time, Lake Shore does not perform recalibrations on finished probes.

Configured options

A = Probe length

Probe length
1 to 28 

Offered in whole inch increments from 1 in to 28 in

 

 

B = Tube diameter1

Tube diameter
2 

1/8 in

4 

1/4 in

1Probes over 20 inches long are only available in 1/4-inch diameter

 

 

C = Probe mount

Probe mount
N 

No probe mount adapter

S 

Swagelok® fitting2

F 

CF flange fitting3

2For 1/8 in diameter probe, Swagelok® fitting uses a 1/8 in NPT male thread;
for 1/4 in diameter probe, Swagelok® fitting uses a 1/4 in NPT male thread
3The CF™ flange is welded to the probe-1

 

 

D = External cable/wire type4

External cable/wire type
N 

No external cable (usually used with Detoronics connector)

S 

S1 coaxial cable (2-lead)

I 

30 AWG instrument cable (4-lead)

 

DT-32 (twisted pair of 32 AWG phosphor bronze wire)

F 

QT-32 (two twisted pairs of 32 AWG phosphor bronze wire)

Q 

QT-36 (two twisted pairs of 36 AWG phosphor bronze wire)

L 

QL-32 (four 32 AWG wires in a ribbon configuration)

C 

CryoCable™ (4-lead cryogenic coaxial cable)

4Lake Shore strongly recommends that all RTD temperature sensors use a 4-lead cable/wire type

 

E = Terminator

Terminator
N 

No connector (leads stripped and tinned)

B 

BNC connector

D 

10-pin Detoronics connector5

Y 

25-pin D-shell connector for temperature monitors

R 

Connector wired for temperature instruments (6-pin round)

5Selecting a Detoronics connector limits the following selections: d = N and f = 0;
the Detoronics connector is o-ring sealed to the probe

 

 

F = External cable length

External cable length
1 to 10 

Offered in whole meter increments from 1 m to 10 m

Enter ‘0’ for no external cable

 

 

G = Temperature sensor type6

Temperature sensor type
Down arrow 

Specify sensor model number with calibration range, if applicable

6Due to indium solder use, all SD sensors have an upper temperature usage limit of 400 K

 

 


   
Cernox Silicon diodes
   
   
Platinum