HNT70 Magnetic Mount Surface Temperature Sensor (Pt100 / K Type, –50…200 °C)

The HNT70 is a magnetic-mounted surface temperature sensor built for quick, non-invasive attachment to steel equipment. A strong magnetic base holds the probe flat on the metal surface; the probe and base are seamlessly welded for a durable, break-resistant joint. Choose a Pt100 or K-type element, a braided high-temperature lead and a lead termination to match your instrument. Cable length, element and magnet assembly can be customized to the application.

INQUIRY / REQUEST A CUSTOM BUILD

Quick Surface Mounting Without Drilling or Welding

Place the magnetic base on a ferrous steel surface and the probe sits against it — no thread, flange or mounting hole required. It suits temporary checks, retrofit monitoring and condition monitoring on motors, pumps, compressors, bearing housings and machine frames. The high-temperature magnet keeps its adhesion up to 200 °C; the seamless welded construction avoids the plug-in breakage seen on assembled magnetic probes.

Good fit: motor and generator housings, motor and pump bearing housings, compressor and gearbox surfaces, machine tool frames and steel structures, heating plates and roller surfaces, temporary or retrofit surface temperature checks, plant condition monitoring, steel-equipment surface temperature measurement.

Is HNT70 Suitable for Your Application?

Choose HNT70 when:

• You need a surface temperature reading on a ferromagnetic steel part, mounted without drilling or threading.

• Surface temperature is within –50…200 °C, and a passive Pt100 resistance or K-type thermocouple signal is acceptable.

• You want a flexible, customizable build: element type, cable length and lead termination matched to your instrument.

Confirm with us first when: the part is aluminum, copper or austenitic stainless steel (the magnet will not hold), the surface is heavily painted or coated, temperature exceeds 200 °C, or you need an integrated 4–20 mA / HART / RS485 transmitter.

Why a Magnetic-Mount Probe

Seamless welded construction

The probe and magnetic base are seamlessly welded, giving a stronger joint with no detachment risk, instead of a plug-in assembly that can work loose or break.

High-temperature magnetic stability

The magnet is rated to maintain strong adhesion up to 200 °C, where ordinary magnetic probes start to lose holding force and demagnetize.

Custom element, cable and termination

Pt100 (3-wire standard) or K-type thermocouple; braided high-temperature lead; ferrules, plugs or other termination on request. Cable length and magnet assembly are built to your application.

Technical Specifications

Selection Options

HNT70 is built to order. Send your requirements and we will confirm the element, cable and magnet arrangement.

Installation Notes

Clean the mounting surface of loose paint, rust and dirt so the base sits flat and makes good thermal contact. The magnet holds on ferromagnetic steel; it will not adhere to aluminum, copper, austenitic stainless steel or smooth non-ferrous surfaces. Keep the braided lead away from moving parts and sharp edges, and route it clear of heat sources above the cable rating. For long lead runs, prefer the 3-wire Pt100 to limit lead-resistance error.

Typical Applications

• Motors and generators: housing and bearing-housing surface temperature monitoring.

• Pumps, compressors and gearboxes: surface checks during commissioning and condition monitoring.

• Machine frames and steel structures: temporary or retrofit surface measurement without drilling.

• Heating plates and rollers: flat-surface temperature reading where a contact probe can be magnet-held.

What to Send Us for a Custom Build

Send: target surface material and whether it is magnetic steel, surface temperature range, element preference (Pt100 or K), cable length, lead termination or instrument connector, and any mounting clearance or vibration conditions. We will confirm the magnet fit and build arrangement before quoting.

Frequently Asked Questions

Does the magnet stick to stainless steel or aluminum?

Only to ferromagnetic (magnetic) steel. It will not hold on aluminum, copper, austenitic stainless steel or other non-ferrous surfaces. Tell us the part material if you are unsure.

Pt100 or K-type — which should I choose?

Pt100 gives better accuracy and stability over –50…200 °C on a 3-wire or 4-wire connection; the K-type thermocouple suits cost-sensitive or higher-temperature surface duties. For this 200 °C range, Pt100 is the usual choice.

Can the cable length be customized?

Yes. The braided lead is offered in standard lengths or built to a custom length; specify the termination to match your indicator, recorder or PLC input.

Will the magnet demagnetize at 200 °C?

The high-temperature magnet keeps its adhesion up to the 200 °C rating. Avoid sustained exposure above the rating, and keep the base flat against the surface for full holding force.

Can a 4–20 mA transmitter be added?

The standard probe is passive. A transmitter head can be integrated on request for 4–20 mA, HART or RS485 output — note this in your enquiry.

Datasheet Download

View HONNO temperature sensors and product manuals on our Download page »

Need a Custom Magnetic Probe?

Send us the surface material, temperature, cable length and termination. We will confirm the magnet fit and build it to your instrument.

Send us your application details »