About Selecting Temperature Sensors
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Bayonet-Mount Thermocouple Probes for Surfaces
Quick to install and remove, these probes won’t shake loose from a surface even in high-vibration environments. Twist their bayonet fitting into an adapter mounted on your surface to hold them in place. Their tip is exposed, so they can respond to rapid changes in surface temperatures but can’t be used in liquids. For accurate readings, move the fitting along the length of the cable until the tip of the probe is pressing firmly against the surface you’re measuring. To prevent wear, corrosion, and abrasion, an armored stainless steel cable protects the wiring that connects these probes to your temperature-monitoring device. This makes these probes a good choice for humid and harsh environments.
Pick the thermocouple type that best covers the temperature range you expect your surface to be. You should also make sure the thermocouple type you choose is compatible with the device you plan to connect it to. These probes are often used with temperature controllers and thermometers.
These probes are manufactured to conform to ASTM E230 for accuracy. Accuracy is how far off the reported value is from the actual temperature.
Choose a probe with spade or ring terminals if you plan to connect to a terminal block. For installation, note that the red wire lead is negative.
Probes with a cord grip are easy to secure to an enclosure or conduit box. The cord grip reduces strain on the cable when it’s pulled or twisted. You can also remove it.




Probe | Cable | Wire | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Lg. | Dia. | Response Time, sec. | Max. Temp., °F | Accuracy | Probe Material | Sensor Type | Material | Max. Temp. °F | Lead Lg. | Gauge | 4 ft. Cable Lg. | 6 ft. Cable Lg. | 8 ft. Cable Lg. | 10 ft. Cable Lg. | |
Type J—Flat-Pin Mini Thermocouple Connector | |||||||||||||||
1/2" | 3/16" | 2.5 | 900° | ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | __ | __ | 0000000 | ||||
Type J—Round-Pin Thermocouple Connector | |||||||||||||||
1/2" | 3/16" | 2.5 | 900° | ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | __ | __ | 0000000 | ||||
Type J—Spade Terminals | |||||||||||||||
1/2" | 3/16" | Not Rated | 900° | ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Ungrounded | Stainless Steel | 900° | 3" | 20 | 0000000 | ||||
1/2" | 3/16" | 2.5 | 900° | ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | 3" | 20 | 0000000 | ||||
Type K—Flat-Pin Mini Thermocouple Connector | |||||||||||||||
1/2" | 3/16" | 2.5 | 900° | Not Rated below 32° F ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | __ | __ | 0000000 | ||||
Type K—Round-Pin Thermocouple Connector | |||||||||||||||
1/2" | 3/16" | 2.5 | 900° | Not Rated below 32° F ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | __ | __ | 0000000 | ||||
Type K—Spade Terminals | |||||||||||||||
1/2" | 3/16" | Not Rated | 900° | Not Rated below 32° F ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Ungrounded | Stainless Steel | 900° | 3" | 20 | 0000000 | ||||
1/2" | 3/16" | 2.5 | 900° | Not Rated below 32° F ±4° F between 32° to 533° F ±0.75% above 533° F | 304 Stainless Steel | Grounded | Stainless Steel | 900° | 3" | 20 | 0000000 |


Probe | Cable | Wire | 3 ft. Cable Lg. | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Lg. | Dia. | Response Time, sec. | Max. Temp., °F | Accuracy | Probe Material | Sensor Type | Material | Max. Temp. °F | Lead Lg. | Gauge | Each | |
Type J—Ring Terminals | ||||||||||||
1/4" | 3/16" | 8 | 1150° | ±4° F between 32° to 533° F ±0.75% above 533° F | 316 Stainless Steel | Grounded | Stainless Steel | 900° | 2" | 20 | 0000000 | 000000 |
Type K—Ring Terminals | ||||||||||||
1/4" | 3/16" | 8 | 1700° | Not Rated below 32° F ±4° F between 32° to 533° F ±0.75% above 533° F | 316 Stainless Steel | Grounded | Stainless Steel | 900° | 2" | 20 | 0000000 | 00000 |