TEMPERATURE MEASUREMENT SOLUTIONS

Temperature Sensors & Transmitters

Industrial thermocouples, RTD sensors, temperature transmitters, and bimetallic thermometers for process temperatures from -200 to 1800°C. Available in sheathed, assembled, and explosion-proof configurations with 4-20mA, RS485, and HART outputs.

Temperature Sensors and Transmitters by HMK TECH

Complete Temperature Measurement Solutions

HMK manufactures a full range of industrial temperature instruments covering thermocouple, RTD, transmitter, and mechanical thermometer technologies. Our products serve applications from cryogenic storage at -200°C to high-temperature furnaces at 1800°C, with sensing elements, protection tubes, and signal conditioning designed to work together as integrated measurement systems.

Each product line is available in multiple configurations — sheathed designs for compact installations, assembled types with replaceable elements for easy maintenance, and explosion-proof versions certified for hazardous areas. Head-mounted and rail-mounted transmitters convert sensor signals to standard 4-20mA or digital outputs for direct integration with PLCs, DCS, and SCADA systems.

TC SERIES

Industrial Thermocouples

Type K, J, T, N, E, S, R, and B thermocouples for temperatures from -200 to 1800°C. Available in sheathed, assembled, and explosion-proof configurations.

Sheathed Thermocouples

Sheathed Thermocouples

Mineral-insulated Type K/J/T/N/E/S/R/B thermocouples with 316L SS or Inconel 600 sheath. Temperature range -200 to 1300°C. Fast response, high vibration resistance.

Assembled Thermocouples

Assembled Thermocouples

Modular industrial thermocouples with replaceable sensing elements. Junction box or connection head mounting. Suited for furnaces, reactors, and pipelines.

Explosion-Proof Thermocouples

Explosion-Proof Thermocouples

NEPSI-certified dII BT4/CT5 explosion-proof thermocouples for hazardous environments. Flameproof enclosure with Type K/N/E/J/T elements.

RTD SERIES

RTD Temperature Sensors

Pt100 and Pt1000 resistance temperature detectors with Class A and Class B accuracy per IEC 60751. Higher accuracy and better stability than thermocouples below 600°C.

Sheathed Thermal Resistance (RTD)

Sheathed Thermal Resistance (RTD)

Pt100/Pt1000 mineral-insulated RTD probes. Class A/B accuracy per IEC 60751. Compact design for tight spaces, 2/3/4-wire configurations available.

Assembled Thermal Resistance (RTD)

Assembled Thermal Resistance (RTD)

Modular Pt100 RTD assemblies with thermowell and connection head. Fixed or adjustable insertion length for industrial process monitoring.

Explosion-Proof Thermal Resistance (RTD)

Explosion-Proof Thermal Resistance (RTD)

NEPSI-certified explosion-proof Pt100 RTD assemblies for hazardous areas. Flameproof junction box with Class A accuracy option.

TRANSMITTER SERIES

Temperature Transmitters

Head-mounted and DIN rail temperature transmitters that convert thermocouple or RTD signals to standard 4-20mA, 0-10V, or RS485 outputs.

SBW Temperature Transmitter

SBW Temperature Transmitter

Head-mounted 4-20mA temperature transmitter for TC and RTD inputs. DIN B connection head, ±0.2% accuracy. Replaces long thermocouple cable runs.

HM100 Temperature Transmitter

HM100 Temperature Transmitter

DIN rail or panel mount temperature transmitter with universal TC/RTD input. 4-20mA or RS485 output, programmable via push buttons or HART.

Explosion-Proof TC/RTD with Transmitter

Explosion-Proof TC/RTD with Transmitter

Integrated explosion-proof temperature assembly with built-in 4-20mA transmitter. One-piece design eliminates separate transmitter installation.

MECHANICAL

Mechanical Temperature Instruments

Bimetallic dial thermometers for local temperature indication without power supply. Rugged 304 stainless steel construction.

Bimetallic Thermometers

Bimetallic Thermometers

Industrial bimetallic dial thermometers with 304 SS case. Back, bottom, or adjustable angle connection. Ranges from -80 to 600°C.

ACCESSORIES

Temperature Sensor Accessories

Industrial Thermowells TF Series

Industrial Thermowells (TF Series)

Protective thermowells for RTDs and thermocouples in high-pressure and high-temperature environments. Available in flanged, threaded, and welded configurations. Materials include 304SS, 316SS, and Inconel for demanding process conditions.

Temperature Sensor Selection Guide

Use this comparison to select the right sensor technology for your application.

ParameterThermocouplesRTD (Pt100)Transmitters
Temperature Range-200 to 1800°C-200 to 600°CDepends on input
Accuracy±1.5°C (Class 1)±0.15°C (Class A)±0.2% FS
Response TimeFast (t₀.₅ < 5s)Moderate (t₀.₅ < 8s)N/A
StabilityModerateExcellentExcellent
OutputmV signalResistance (Ω)4-20mA / RS485
Best ForHigh temp, fast responsePrecision <600°CLong cable runs

Frequently Asked Questions

Thermocouples generate a voltage proportional to temperature and measure up to 1800°C. RTDs measure temperature through the change in electrical resistance of platinum wire, offering higher accuracy (±0.15°C Class A) but limited to about 600°C. Choose thermocouples for high temperatures and fast response; choose RTDs for precision below 600°C.

Type K (Chromel-Alumel) is the most common, covering -200 to 1260°C with good general-purpose performance. Type J works for reducing atmospheres up to 750°C. Type T offers excellent accuracy at low temperatures (-200 to 350°C). Type N provides better stability than K at high temperatures. Noble metal types S, R, and B handle above 1300°C in oxidizing environments.

2-wire RTDs are simplest but include lead wire resistance error. 3-wire connections (most common) compensate for lead resistance using a bridge circuit. 4-wire configurations eliminate lead resistance entirely for maximum accuracy. For cable runs under 10 meters with Class B tolerance, 3-wire is sufficient. For Class A accuracy or long cable runs, use 4-wire.

Temperature transmitters are recommended when cable runs exceed 15 meters, when you need a standard 4-20mA loop for PLC input, when operating in electrically noisy environments, or when you want to simplify wiring by converting at the sensor location. Head-mounted transmitters (SBW series) install directly in the sensor connection head.

Yes. Our explosion-proof thermocouples and RTDs carry NEPSI certification with classifications including dII BT4 and dII CT5, suitable for Zone 1 and Zone 2 explosive gas atmospheres. The flameproof enclosure prevents internal sparks from reaching the surrounding atmosphere.

All products are available with custom insertion lengths (50 to 2000mm or longer), alternative sheath materials (304 SS, 316L SS, Inconel 600, Hastelloy C276), various process connections (threaded, flanged, compression fitting), and different wire configurations. Contact our engineering team to discuss your requirements.

Need Help Selecting the Right Temperature Sensor?

Our temperature measurement engineers can recommend the optimal sensor type, configuration, and mounting for your specific application. Share your process conditions and we will provide a detailed technical proposal.

Our engineers typically respond within 12 business hours with detailed technical specifications and pricing.