For a temperature controller, first look at “which sensor it connects to” (input), then “what it has to drive” (output), next choose the control method (on/off, PID or multi-step program), and then confirm the panel size and communication. If any one of the four does not match, you have bought something that cannot be fitted, or that can be connected but cannot be used. This article splits selection into 4 stages:
Stage ① | Input: whether the sensor is a thermocouple, a platinum resistance temperature detector or a thermistor; what the temperature range is.
Stage ② | Output: whether the load is connected directly, or through a solid-state relay (SSR) or an analog signal.
Stage ③ | Control: on/off, PID (with auto-tuning), or programmable multi-step.
Stage ④ | Size and communication: panel cutout, supply voltage, and whether it has to connect to a PLC or monitoring system.
For how to measure temperature accurately, see “How to Measure Flame Brazing Temperature? Limits of Non-Contact Measurement and the Right Approach“; this article starts from “the temperature is measured — what controller should manage it”. Each stage below covers: how to do it, what public sources say, and what Jiahon can help with; sources, exceptions and this article’s own summaries are in the “Notes” at the end.
Figure 1: The four stages of temperature controller selection (schematic, not to scale). ① Input — thermocouple: common types K and J; platinum resistance temperature detector; thermistor; temperature range: change type if out of range. Result of this step: input type matches the sensor. ② Output — relay: small loads, infrequent switching; SSR drive: outputs pulses to drive an external element; analog signal: power regulators, valves, recorders. Result: the output matches the voltage and current of the load. ③ Control — on/off: temperature swings above and below the setpoint; PID (with auto-tuning): holds near the setpoint; programmable multi-step: follows a temperature profile. Result: one method chosen by the stability required. ④ Size and communication — panel cutout: go by the dimensions in the specification sheet; supply voltage: AC or DC, how many volts; communication: connect to a PLC or monitoring system. Result: cutout, power and communication all match.
Stage ①: Input — which sensor it connects to
How to do it:
First look at the sensor already on site, or about to be installed: thermocouple (common types K and J), platinum resistance temperature detector (Pt100), thermistor (NTC).
The controller’s input type must match the sensor. A model with “universal input” lets you change the input type in the settings, so if you change the sensor later, you do not have to change the controller (this article’s own summary).
Then look at the temperature range: type K about −200 to 1,260 °C, type J about −40 to 750 °C; if the temperature to be measured is beyond the range, change the type.
For accuracy below 500 °C, consider Pt100 first; for a wide range, durability and fast response, use a thermocouple.
What public sources say: the US National Institute of Standards and Technology (NIST) provides a database of thermocouple temperature-voltage reference tables; thermocouple tolerance classes are set by a standard of the International Electrotechnical Commission (IEC). A public blog on an industrial website summarizes on this basis: the Class 1 tolerance for both type K and type J is ±1.5 °C or ±0.4% of reading; the iron wire of type J rusts in humid environments, and type K may drift between 300 and 500 °C; Pt100 has better accuracy and stability (notes table 1).
What Jiahon Can Help With:
48×96 mm full-display temperature controller: three inputs — K, J and PT100 — switched on the front panel, no jumpers needed; range type K 0 to 1,200 °C, type J 0 to 900 °C, PT100 0 to 600 °C.
Full-display temperature controller (96×48 mm): 18 inputs (10 thermocouple types, 2 platinum resistance types, 6 DC current/voltage types).
48×48 mm temperature controller (type K): type K thermocouple input, range 0 to 399 °C, accuracy ±1 °C.
Temperature controller for refrigeration and freezing: NTC/PTC input, control range −50.0 to +110.0 °C; −55.0 to +150.0 °C with Pt1000.
PID auto-tuning temperature controller series: the product page says the whole series supports thermocouple and platinum resistance (RTD) inputs, and three of the models can also take analog inputs.
Programmable multi-step temperature controller series: the product page says universal input, supporting various thermocouples and platinum resistance (RTD) sensors.
Sensors: the site has thermocouples and temperature wires for oven profiling; for sensors to connect to a temperature controller, please inquire.
Stage ②: Output — what it has to drive
How to do it:
First write down the load: the heater’s voltage and current, and whether it is connected directly or through a solid-state relay (SSR) or contactor.
Then match the output type:
| Output type | How it works | Used for |
|---|---|---|
| Relay | A mechanical contact inside the controller switches the load directly | Small loads, infrequent switching |
| SSR drive | The controller outputs a pulse voltage to drive an external SSR | When PID needs frequent switching |
| Analog (for example 4 to 20 mA) | Outputs a continuous signal | Driving power regulators and valves; or sending to recorders and PLCs |
- When using an SSR, its current rating should be at least 25% higher than the heater load. Mechanical contacts have a limited life, so where switching is frequent, use SSR drive instead (this article’s own summary).
What public sources say: a public page of a temperature controller maker lists the outputs of an entry-level model: relay 250 V, 2 A; logic output (SSR drive) a 9 V, 18 mA pulse; the time-proportioning cycle can be set from 0.2 to 100 seconds. An industrial control knowledge website writes that thermal systems use SSRs for time-proportioning control, with a cycle of about 2 to 10 seconds, and the SSR’s current rating at least 25% above the load (notes table 2).
What Jiahon Can Help With:
48×96 mm full-display temperature controller: control output is a voltage pulse of 12 V DC / 50 mA, which the product page says is for driving an SSR; there are also 2 relay alarm outputs of 3 A / 250 VAC.
48×48 mm temperature controller (type K): 15 A relay output, which the product page says can be used to trigger an SSR or drive a small heater directly.
Temperature controller for refrigeration and freezing: 1 SPDT relay, 8(4) A / 250 Vac, which the product page says can drive a compressor directly.
Full-display temperature controller (96×48 mm): 4 to 20 mA DC retransmission output (load 550 Ω or less), 3 alarm outputs; the type of control output is not stated on the product page; please inquire.
Programmable multi-step temperature controller series: the three models have different control outputs; the comparison table on the product page lists “SSR/relay”, “relay” and “dual control output”.
PID auto-tuning temperature controller series: the four models have different outputs; the model table on the product page lists relay, current output, and a combination of current plus relay.
SSRs and heaters: if you need them, please inquire.
Stage ③: Control — on/off, PID or a multi-step program
How to do it: first decide how stable the temperature has to be:
| Control method | How it works | Used for |
|---|---|---|
| On/off | Turns on below the setpoint and off above it; the temperature swings above and below the setpoint | Heating or refrigeration without demanding stability requirements (this article’s own summary) |
| PID (with auto-tuning) | Adjusts the output by the deviation; auto-tuning lets the controller find the parameters itself | Holding steady near the setpoint |
| Programmable multi-step | A multi-step profile of ramp, soak and cool-down set in advance | Processes that must follow a temperature profile |
What public sources say: a public page of a temperature controller maker says the entry-level model offers on/off or PID, with auto-tuning and overshoot suppression, and can also limit the rate of change of the setpoint; the advanced model can program 16 segments of ramp and soak and has several recipes (notes table 2).
What Jiahon Can Help With:
48×48 mm temperature controller (type K): on/off or simple PID, set by DIP switches; the product page states it does not have a full auto-tuning function.
48×96 mm full-display temperature controller: PID auto-tuning, control accuracy ±0.1% of range; dual-line LED showing the actual temperature (PV) and setpoint (SV) at the same time.
PID auto-tuning temperature controller series: PID auto-tuning in one key press; the 96×96 mm model also lists multiple setpoints and a program function.
Programmable multi-step temperature controller series: auto-tuning PID; the product page mentions multi-step setpoint switching (one model stores 4 setpoints). Whether a time profile of ramp, soak and cool-down can be set is not stated on the product page; please inquire.
Full-display temperature controller (96×48 mm) and temperature controller for refrigeration and freezing: the control method is not stated on the product pages; please inquire.
Stage ④: Size and communication
How to do it:
Measure the panel cutout; do not go just by the size in the product title. Common panel sizes are 48×48 mm, 48×96 mm and 96×96 mm (commonly called 1/16, 1/8 and 1/4 DIN); whether these figures refer to the bezel or the cutout, and the body depth, go by each model’s specification sheet.
Check the supply voltage: before ordering, confirm whether the panel supply is AC or DC, and how many volts.
Communication or not: to send the temperature to a PLC or monitoring system, choose a model with RS485 or Modbus.
What public sources say: a public online encyclopedia page says DIN 43700 has been replaced by IEC 61554, and lists 1/16 DIN as 48×48 mm, 1/8 DIN as 96×48 mm and 1/4 DIN as 96×96 mm; the page calls these sizes cutout dimensions (notes table 3). This article did not read the full text of IEC 61554, so it does not judge whether the numbers in the size names refer to the bezel or the cutout. The specification tables on two of Jiahon’s product pages give 48×48 mm and 48×96 mm as outer dimensions, with the cutout listed separately; the two accounts differ, so when measuring the panel, please go by the cutout column of each model’s specification sheet.
What Jiahon Can Help With:
48×48 mm temperature controller (type K): outer dimensions 48×48×60 mm, cutout 44×44 mm; power AC 220 V.
48×96 mm full-display temperature controller: outer dimensions 48×96×100 mm, cutout 45×92 mm; power AC 90 to 265 V (wide voltage).
Full-display temperature controller (96×48 mm): the size is given as 96×48 mm, and the product page does not say whether this is the outer size or the cutout; please inquire; power 100 to 240 VAC; communication is not stated on the product page; please inquire.
Programmable multi-step temperature controller series: in the size column of the product page, two models are 48×96 mm and one is 96×96 mm; power within AC 85 to 265 V (the three models have different ranges); the 96×96 mm model lists RS485 communication.
Temperature controller for refrigeration and freezing: power AC 190 to 250 V; TTL port, which the product page says can connect a copy card or Modbus monitoring; the size is not stated on the product page; please inquire.
PID auto-tuning temperature controller series: four models — DIN rail type (22.5 mm wide), 48×48 mm panel type, 96×96 mm panel type and standard type; the standard type lists RS485 communication; the size of the standard type is written inconsistently between the product page text and the model table; please inquire; the power supply is not stated on the product page; please inquire.
For the first two models, the outer size and cutout are given separately, and the cutout is 3 to 4 mm smaller than the outer size in each case; for the cutout and body depth of the other models, please inquire.
Further reading
To go through the related process steps together, you can read these next:
- “How to Measure Flame Brazing Temperature? Limits of Non-Contact Measurement and the Right Approach“: how to measure temperature, and the limits of measurement methods
When you need to match a type, please prepare four items first: the sensor type and temperature range, the voltage and current of the load, the control requirements, and the panel cutout and power supply. You are welcome to contact Jiahon.
Further reading: “Temperature Controller vs PLC“, “Temperature Controller vs Temperature Data Logger“
Notes: sources and exceptions
The following is for readers who need to check; skipping it does not affect the approach above. Where your process specifications or the written specifications of your temperature controller and sensor differ from this article, follow them.
Where each stage comes from
| Stage | Content | Source |
|---|---|---|
| Input | Thermocouple temperature-voltage reference database | Overview of the NIST ITS-90 Thermocouple Database (source 1, version 3.0, created September 2023, updated April 2024) |
| Input | Temperature ranges and tolerances of types K and J; characteristics of Pt100 | A public blog on an industrial website: thermocouple types (source 2, page in Polish, dated July 7, 2026) |
| Output, control | Inputs, outputs and control methods of entry-level and advanced controllers | A public page of a temperature controller maker (source 3, page information marks December 3, 2018) |
| Output | Driving an SSR by time proportioning | An article on an industrial control knowledge website (source 4, April 19, 2026) |
| Size | Names of panel sizes and bezel dimensions | A public online encyclopedia page: DIN 43700 (source 5, no date on the page) |
| Jiahon’s own data | Titles of each product page, published articles | Jiahon product pages and articles |
Table 1 | Thermocouples and resistance temperature detectors
| Item | Type J | Type K | Pt100 |
|---|---|---|---|
| Temperature range | −40 to 750 °C | −200 to 1,260 °C | No figure given in the blog |
| Class 1 tolerance | ±1.5 °C or ±0.4% | ±1.5 °C or ±0.4% | No figure given in the blog |
| Notes | Iron wire rusts in humid environments | May drift at 300 to 500 °C; degrades in reducing or sulfur-containing environments | Better accuracy and stability |
Source: source 2 (the blog cites IEC 60584-1). The blog also says: for accuracy below 500 °C, consider an RTD first; for a wide range, durability and fast response, use a thermocouple; the millivolt signal of a thermocouple is more susceptible to noise over long cable runs.
Table 2 | Public statements on outputs and control methods
| Item | Content | Source |
|---|---|---|
| Relay output | 250 V, 2 A | Source 3 |
| Logic output (SSR drive) | 9 V, 18 mA pulse | Source 3 |
| Time-proportioning cycle | 0.2 to 100 seconds | Source 3 |
| SSR cycle in thermal systems | About 2 to 10 seconds | Source 4 |
| SSR current rating | At least 25% above the load | Source 4 |
| Control methods | Entry-level: on/off or PID, with auto-tuning and overshoot suppression; the rate of setpoint change can be limited (0.01 to 99.99 degrees or units per minute) | Source 3 |
| Advanced model | 16-segment ramp and soak program, several recipes; also auto-tuning, adaptive tuning, dual heat/cool outputs and so on | Source 3 |
| Inputs (entry-level) | Thermocouples J, K, T, L, N, R, S, B, C and others; Pt100 (two-wire); millivolt −12 to 80 mV; 4 to 20 mA | Source 3 |
Table 3 | Panel sizes
| Size name | Dimensions (the page calls them cutout dimensions) |
|---|---|
| 1/16 DIN | 48×48 mm |
| 1/8 DIN | 96×48 mm |
| 1/4 DIN | 96×96 mm |
| 1/2 DIN | 192×96 mm |
| 1/32 DIN | 24×48 mm |
Source: source 5. The page says DIN 43700 has been replaced by DIN IEC 61554, and describes it as specifying the nominal dimensions of panel bezels and cutouts for measuring and control instruments; the page calls the figures in the table cutout dimensions and does not list separate bezel figures.
Standards referenced
For the standards cited in this article, please follow the current revision from each publishing body.
ITS-90 Thermocouple Database (SRD 60) — overview
Publisher: US National Institute of Standards and Technology (NIST)IEC 60584-1 “Thermocouples — Part 1: EMF specifications and tolerances”
Publisher: IEC (International Electrotechnical Commission)IEC 61554 “Panel mounted equipment — Electrical measuring instruments — Dimensions for panel mounting”
Publisher: IEC (International Electrotechnical Commission)
This is the general case and still depends on the individual case.
Exceptions and limits
What was seen and what was not: this article looked at the overview page of the NIST thermocouple database, a thermocouple blog on an industrial website, a public page of a temperature controller maker, an article on an industrial control knowledge website, and an online encyclopedia page; the full texts of IEC 60584-1 and IEC 61554 were not read (the current edition of IEC 61554 is the 2nd edition of May 2025, and just a summary on a standards publisher’s page was seen). The NIST page does not list the temperature ranges of types K and J, so the ranges were taken from the blog; no public source for the numerical range of Pt100 was found, so it is not given.
Dimensions in IEC 61554: the standard’s own web page blocks automated reading, and this article did not get around that, so for dimensions it quotes just the size names and dimensions listed on the online encyclopedia page; that page calls the figures cutout dimensions, while the specification tables on two of Jiahon’s product pages (48×48 mm, 48×96 mm) give these two figures as outer dimensions, with the cutouts listed separately as 44×44 mm and 45×92 mm. The two accounts are inconsistent, and since this article did not read the full text of IEC 61554 it cannot judge; please go by the cutout column of each model’s specification sheet.
Sources with a position: the explanations by the temperature controller maker, the industrial website and the industrial control website have a sales or promotional position; the maker’s page just takes two series as examples and does not represent the specifications of other brands.
Dates: the NIST page was updated in April 2024; the industrial website’s blog is dated July 7, 2026 (page in Polish, with figures taken from its table); the industrial control knowledge website is dated April 19, 2026; the temperature controller maker’s page has page information marked December 3, 2018, its specifications are old, and it is used just to illustrate the kinds of outputs and control methods; the online encyclopedia page has no date.
This article’s own summary: the following are this article’s summaries based on the sources, not written this way in the sources: “universal input means you do not have to change the controller” is inferred from the definition of universal input; “mechanical contacts have a limited life, so use SSR drive for frequent switching” and the “Used for” column of the output type table are this article’s generalizations, and the sources do not discuss the life of mechanical contacts; the “Used for” entry for on/off is this article’s suggestion, and those for PID and multi-step are inferred from their functions; the steps of measuring the cutout and confirming power and communication are this article’s suggestions.
Scope: this article does not discuss sensor installation and calibration, heater selection or how to tune PID parameters, nor prices and lead times.
Equipment and products: the figures and statements in “What Jiahon Can Help With” were read from the text of each product page on October 13, 2026; the product images were not looked at, and they were not verified by this article; the specification is as on each product page, and for what the product page does not state, please inquire.
This article is a summary for the general case, not a restatement of standard clauses, and not an endorsement of any maker, equipment supplier or service provider, nor an assurance for your products and processes. Please take your process specifications, the written specifications of your temperature controller and sensor, and your own validation as the reference; this is the general case and still depends on the individual case.