We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Red infrared thermometer ST-685, rugged compact design, 30:1 or 50:1 distance-to-spot ratio

Sentry

Sentry ST-685 electrician tool infrared thermometer -50~1000°C 30:1 50:1 DS ratio

SKU CH-JPNY-2V2FF MPN ST-685

Non-contact infrared thermometer measures -50 °C to 1000 °C with 30:1 or 50:1 distance-to-spot ratio for safe long-range readings

  • Labor warranty1 Year
  • Color and finishRed
  • Number of items1 pack
  • Sold asBox
  • Parts warranty3 Years
  • Measures extreme heat up to 1,000 °C for industrial electrical inspections
  • Dual distance-to-spot ratios of 30:1 and 50:1 enable accurate readings from far away
  • Reads down to -50 °C for cold-storage and refrigeration diagnostics
  • Fine 0.1 °C resolution detects small temperature changes on circuits
  • Rugged compact housing built for long-distance measurement tasks

What it measures and who uses it

The Sentry ST-685 is a non-contact infrared thermometer built for electricians and technicians who need to check surface temperatures from a safe distance. It covers a range of -50 °C to 1,000 °C with a resolution of 0.1 °C. The rugged, compact housing suits daily use on job sites and in maintenance routines.

Distance-to-spot ratio decides the range

This model offers a selectable distance-to-spot ratio of 30:1 or 50:1, letting you measure smaller targets at greater distances than standard units. A higher ratio means the measurement spot stays tight on busbars, motor windings or transformer terminals without climbing ladders or opening live cabinets.

What the tool needs around it

The thermometer runs on standard batteries and requires a clear line of sight to the target surface; emissivity settings handle common materials but polished metal may need tape or paint for accuracy. It frees you from contact probes on live circuits and speeds up panel surveys, though it cannot measure air temperature or internal component heat.

How it compares

Measured against everything we stock in Electrical Trade Tools & Kits, at today’s prices. Recalculated every night.

Price $652.99
Pricier than about 91% of the 5,006 comparable items (median $95.99).

Specifications

Product
Brand nameSENTRY
Model nameST-685
Color and finishRed
In the box
Number of items1 pack

Questions about this item

What does the 1000°C top end mean when I am measuring a live panel?

The ST-685 reads surface temperatures up to 1000°C, so you can check hot spots on breakers, busbars or motor windings without contact.

How do the 30:1 and 50:1 distance-to-spot ratios limit the smallest target I can measure?

At 30:1 a 30 cm spot is measured from 9 m away; at 50:1 the same spot size is reached from 15 m, letting you read smaller components from further back.

What mounting or power provisions does the ST-685 need for bench use?

The unit is a handheld infrared thermometer powered by internal batteries; no external mount or power supply is required for bench measurements.

More in Electrical Trade Tools & Kits

Similar items