K-Type Thermocouple Acquisition Module

Industrial gradeComponent grade

AC 220VTypical supply

4G/NBUplink

Explosion-proof optionalEnclosure protection

Product overview and engineering role

The SimtoLink K-type thermocouple acquisition module is for high-temperature contact measurement and thermal IoT. The reading follows the IEC 60584 type-K voltage-to-temperature curve. A 24-bit Σ-Δ ADC takes the thermoelectric voltage, and built-in cold-junction compensation (CJC) turns it into degrees Celsius. It is not a platinum RTD PT100 (IEC 60751) scale. What holds up on site is cold-junction accuracy, shield grounding, and EMC wiring. At the hot end, sheath material and insulation aging change Seebeck consistency. Terminals are pluggable, critical chips carry a watchdog and a redundant check, and firmware is signed and can roll back, which is what a volume shipment and later remote service need.

A USB-C debug port and a standard industrial connector are fitted, so the module can sit on an existing SCADA, energy-management, or IoT platform. Southbound point-list templates and northbound MQTT/HTTP push examples shorten the joint debug. Volume orders can add enclosure silkscreen, a set harness length, protocol mapping, and a calibration certificate.

Reliability and field fit

Salt-spray and vibration type tests cover the electrical-safety and EMC items that apply. Ports include surge and reverse-polarity protection. Reinforced grounding and a partitioned layout cut ground-loop and common-mode risk. Outdoor or coastal sites can take a higher ingress rating and a corrosion-resistant coating.

Parameters can be loaded in a batch, thresholds can be set, and models that include it can store event video or a waveform. Configuration and firmware update over the air. Acceptance on site is a power-on self-test, time sync on the communications link, and a sample check. For metering or safety use, SimtoLink helps with a submission to a third-party metrology institute and supplies the type-test file.

Key hardware parameters

The table is a typical build of this module, for selection and for a technical clause in a tender. A wider range, redundant power, or an intrinsically safe version is quoted separately; ask SimtoLink for the hardware specification and the installation and commissioning guide. Order codes in the family can differ slightly. The nameplate and the papers shipped with the module govern.

Parameter	Specification	Notes
Temperature input	Type K thermocouple (NiCr-Ni / NiCr-NiSi)	IEC 60584-1; not a PT100/RTD platinum channel
Cold-junction compensation	Built-in automatic cold-junction compensation (CJC)	Cold-junction temperature plus IEC 60584 voltage-to-temperature conversion and linearization
Temperature range	-200～1200 ℃ (typical build)	The practical upper limit depends on sheath, insulation, and order code; the hardware specification governs
ADC / resolution	24-bit Σ-Δ ADC	Digital filter, mains notch, and sample rate can be set
Accuracy	Typical ±1.0 ℃ (cold junction at 25 ℃)	Single-point or multi-point calibration can tighten it; metering use follows the verification certificate
Supply	DC 5～36 V wide range / AC 220 V (build optional)	Isolated; tied to the wireless and explosion-proof order
Communications	RS485 Modbus RTU; cellular 4G/NB (optional)	Redundancy optional; MQTT/HTTP northbound examples on request
Ingress	IP20～IP67 (by enclosure order)	Outdoor, corrosion-resistant, or explosion-proof housing optional
Power	<2 W (typical, high-power radio transmit not included)	Measured value and the nameplate govern
Isolation withstand	≥1500 VAC (signal/power, typical design)	The type test and the order code govern the exact rating

Typical deployments

Three forms this module usually takes on an IoT job, for design and for judging the return:

Smart campuses and buildings

The K-type thermocouple module joins campus energy management or building controls for submetering, alarms, and policy interlock, so fewer readings are copied by hand.

Manufacturing and energy sites

On a line or in a distribution room the module talks to an MES or EMS, and key process or energy readings are collected at the edge and sent up.

Municipal and utility sites

For scattered points and outdoor cabinets, wide temperature and lightning protection suit water, gas, and street lighting, where the run is long and the delay has to stay short.

Installation, grounding, and maintenance

Confirm supply range and polarity before the module is powered. When needed, measure bus voltage and breaker rating with a multimeter.
Use shielded twisted pair, ground the shield at one end, and do not run it for a long distance bundled with high-power cable.
On the first connection, prove bidirectional read and write and a threshold trip against the platform in the lab, then move the module to site.
Outdoors, give the enclosure a drain path and a way to breathe. Inspect the seal face on rounds. Lightning-protection earth resistance has to meet the local code.
While the module stays in service, take a sample check and archive the logs every 6 months.

Ordering, documentation, and support

SimtoLink can supply the hardware specification, outline drawings, a wiring table, and an example project for this module. Volume orders can include a sample review and inspection at the factory. Warranty and calibration follow the contract and the papers shipped with the module.

Typical applications

A type-K module suits a wide range and a fast contact reading, and in industrial heat work and lab equipment it often sits beside an RTD. The jobs below turn on the medium, the sheath, and how the signal is conditioned.

Heat-treatment furnaces and tunnel kilns

Several type-K zones share one module, for a temperature-uniformity survey and a process-curve record. Common-mode rejection and filtering hold down SCR power control and thyristor phase noise, so a narrow quench window stays inside its temperature limit.

Gas turbines and boiler flues

Flue gas, superheater, and reheater wall temperature support efficiency work, low-NOx firing adjustments, and a metal-creep life estimate. Redundant channels and voting logic cover an SIL bypass comparison and the event record.

Plastic extrusion and rubber curing

Points on the barrel, die, and roll close the loop on melt and mold temperature, so batch color drift and scorch stay down. Modular terminals and a prefabricated harness make a line changeover and a night shift easier.

Calibration of a laboratory furnace

The module is the comparison channel beside a standard platinum resistance thermometer and a thermocouple. It logs cold-junction drift, scan rate, and soak time together. The export template is written so a CNAS original record and an uncertainty statement can cite it.