Omega TH-22 Specification

Thermistor Probes

High Temperature 200°C (392°F)
With M12 Connections

TH-22 Series

Optional

U Maximum Continuous Use, 200°C

(392°F) [Short Term Use to 250°C
(482°F)] for Probe and Connector

U Excellent Long Term Stability
U Tolerance: ±0.2°C From 0 to 70°C

(32 to 158°F)

U Available in 2252, 3K, 5K and 10K Ω

Resistances at 25°C (77°F)

The TH-22 Series thermistor probes are constructed
with the 55000 Series glass encapsulated
thermistor elements which provide excellent
stability and accuracy. The connector design includes
an LCP insert with nickel plated copper pins for high
temperature applications, 200°C (392°F).

With a maximum continuous temperature rating of

-80 to 200°C (-112 to 392°F), and intermittent
operation to 250°C (482°F), these thermistor
sensors can be used in applications previously
out of reach of epoxy coated thermistor sensors.

The probes can be ordered in any length but we
highly recommend a minimum immersion depth
of 1.5". Short probes run the risk of error due
to stem conduction effects.

TH-22B-2252-1/4-0600-M12

M12 4-pin connector

Mounting thread

Probe
length

D

Both models

shown smaller

than actual size.

Probe
length

TH-22A-2252-1/4-0600-M12

Specifications

Temperature Range: -50 to 200°C (-58 to 392°F)
Thermistor Sensor: Refer to Table 1 on next page
Operating Current: 12 micro-amps
Insulation Resistance:

100 MΩ minimum at 100 Vdc
at ambient temperature

Response Time: Approximately
7 seconds (50%), 8 seconds (63.2%),
14 seconds (90%) in water flowing at

0.91 m (3') per second
External Materials: 316L stainless steel

sheath and housing except connector insert
IP Rating: IP67 with mating

connector installed

Resistance Vs. Temperature Characteristics

The Steinhart-Hart Equation has become the
generally accepted method for specifying the
resistance vs. temperature relationship for thermistors.
The Steinhart-Hart equation for temperature as a
function of resistance is as follows:

1

⁄T = A + B [Ln(R)] + C [Ln(R)]

3

where: A, B and C are constants derived from three
temperature test points.

R = Thermistors resistance in Ω
T = Temperature in Kelvins K (°C + 273.15)

Probe

diameter

44.5

(1.75)

32

(1.25)

28.5

(1.125)

Optional extension cable.
Dimensions: mm (in)

M12CM-T24SSPC-SF-2
cable, sold separately.

M12CM-T24SSPC-RF-2
cable, sold separately.

To determine the thermistor resistance at a specific
temperature point, the following equation is used:

(beta-(alpha/2))1/3 – ((beta+(alpha/2))1/3

R = e

where:
alpha = ((A-(1/T))/C)
beta =

SQRT(((B/(3C))3)+(alpha2/4))

The A, B and C constants for each of our thermistor
selections can be found in Table 1. Using these
constants with the above equations, you can
determine the temperature of the thermistor based on

resistance, or determine a thermistors resistance at a

its
particular temperature.

D-1

Probe
Length

38.8

(1.53)

Ø16.7
(0.66)

1

2

3

4

Table 1 Steinhart-Hart Constants

Probe Length

G1/4 BSPP

16 mm Hex

15

(0.59)

40.3

(1.59)

Probe Length

G1/4 BSPP

16 mm Hex

15

(0.59)

40.3

(1.59)

Probe

Length

G1/2 BSPP

27 mm Hex

47.7

(1.88)

18.5

(0.73)

Probe Length

G1/4 BSPP

16 mm Hex

15

(0.59)

40.3

(1.59)

Probe Length

d1

10.2

(0.40)

30

(1.18)

M8X1 Thread1/2" Hex

Probe Length

Probe

Diameter

Typical

1/2-14 NPT

M12X1 Typical

46.2

(1.82)

10.6
(0.42)
Typical

18.2

(0.72)

7/8" Hex

Probe
Length

38.8

(1.53)

Ø16.7

(0.66)

Probe Length

Probe Length

Probe

Diameter

Typical

1/2-14 NPT

M12X1 Typical

46.2

(1.82)

10.6
(0.42)
Typical

18.2

(0.72)

7/8" Hex

3/8-18 NPT

11/16" Hex

38.8

(1.53)

15.2

(0.60)

Probe
Length

38.8

(1.53)

Ø16.7
(0.66)

TH-22A Design

Probe
Length

Resistance

Thermistor

at 25°C

Constant

2252 2252 Ω 1.4705x10

3K 3000 Ω 1.4052x10
5K 5000 Ω 1.2870x10

10K 10,000 Ω 1.1275x10

38.8

(1.53)

Ø16.7
(0.66)

A

B

-3

-3

-3

-3

2.3780x10

2.3692x10

2.3585x10

2.3441x10

TH-22E Design M8x1 Mounting Thread

Probe Length

-4

-4

-4

-4

10.2

(0.40)

Constant

Constant

1.0389x10

1.0125x10

9.4346x10

8.6482x10

30

(1.18)

C

-7

-7

-8

-8

1

TH-22B Design

Probe Length

Probe

Diameter

Typical

⁄2 NPT Mounting Thread

46.2

(1.82)

18.2

(0.72)

1/2-14 NPT

TH-22C Design 3⁄8 NPT Mounting Thread

Probe Length

15.2

(0.60)

38.8

(1.53)

7/8" Hex

10.6

(0.42)

Typical

M12X1 Typical

Dimensions:

mm (inch)

Ø=diameter

Wiring Diagram

2

3

M8X1 Threa

TH-22F Design M10x1 Mounting Thread

Probe Length

1

10.2

(0.40)

M8X1 Thread1/2" Hex

TH-22G Design

Probe

4

Length

18.5

(0.73)

47.7

(1.88)

Single Element

TH-22D Design

Probe Length

3/8-18 NPT

1

⁄4 NPT Mounting Thread

13.4

(0.53)

1/4-18 NPT

35.3

(1.39)

11/16" Hex

9/16" Hex

2

3

Dual Element

1

G1/2 BSPP

TH-22H Design

4

Probe Length

G1/4 BSPP

15

(0.59)

Standard

To Order

Model No. Description
TH-22A-2252-1/4-0600-M12
TH-22B-2252-1/4-0600-M12

Straight sheath, 2252 Ω,
Straight sheath with

1

⁄4" diameter, 6" long, M12 male connector

1

⁄2 NPT mounting, 2252 Ω, 1⁄4" diameter, 6" long,

M12 male connector

3

⁄8 NPT mounting, 2252 Ω, 1⁄4" diameter, 6" long,

1

⁄4 NPT mounting, 2252 Ω, 1⁄4" diameter, 6" long,

1

⁄2 mounting thread, 2252 Ω, 6 mm diameter,

1

⁄4 mounting thread, 2252 Ω, 6 mm diameter,

Straight sheath with
M12 male connector

Straight sheath with
M12 male connector

Straight sheath 2252 Ω, 6 mm diameter, 150 mm long, M12 male connector
Straight sheath with M8x1 mounting, 2252 Ω, 6 mm diameter,

150 mm long, M12 male connector
Straight sheath with M10x1 mounting, 2252 Ω, 6 mm diameter,

150 mm long, M12 male connector
Straight sheath with G

150 mm long, M12 male connector
Straight sheath with G

150 mm long, M12 male connector

TH-22C-2252-1/4-0600-M12

TH-22D-2252-1/4-0600-M12

Metric

Model No. Description
TH-22A-2252-M6-0150-M12
TH-22E-2252-M6-0150-M12

TH-22F-2252-M6-0150-M12

TH-22G-2252-M6-0150-M12

TH-22H-2252-M6-0150-M12

For lengths other than 6", change “-0600” in model number to required length and add additional cost per inch greater than 6",
(example: 9" = 0900, 41⁄2" = 0450).
For 1⁄8" probe diameters, change “-1/4” in model number to “-1/8”, no additional cost.
For 3K, 5K or 10K Ω thermistor elements change “-2252” to desired resistance.
For dual element 1⁄4" or 6 mm diameter versions, add “-DUAL” to the end of the model number (not available in 1⁄8" or 3 mm diameter probes),
for an additional cost.

Ordering Examples: TH-22A-2252-1/4-0600-M12, 1⁄4" diameter probe 6" long with 2252 Ω element, no mounting thread, with M12 connector.
TH-22D-2252-1/4-0600-M12, 1⁄4" diameter probe 6" long with Pt100, Class A element, 1⁄4 NPT mounting thread, with M12 connector.

D-2

40.3

(1.59)

/2" Hex

30

(1.18)

27 mm Hex

16 mm Hex