UK What the industrial temperature range means
The industrial temperature range is −40 to 85 °C: the span an electronic component is specified to work across to be sold as industrial grade. Commercial parts are usually rated 0 to 70 °C, so an industrial part covers 40 °C more at the cold end and 15 °C more at the hot end.
Temperature grades describe the range a component is specified to work across. Processors, memory, storage and power parts each carry their own grade, and a system is only rated as wide as its weakest part. That is why an industrial computer needs industrial-temperature memory and SSDs as well as an industrial processor.
The grade is a manufacturer specification, not a single published standard. Most chip makers use the same −40 to 85 °C figure, which is why it has become the accepted meaning of industrial temperature. Automotive grades are the exception: the Automotive Electronics Council defines them formally in AEC-Q100.
Temperature grades compared
Each step up the grades widens the range a part is tested and screened across. The figures below are the usual ones; always check the datasheet, because extended grades in particular vary between manufacturers.
| Grade | Typical range | Where it is used | Who sets it |
|---|---|---|---|
| Commercial | 0 to 70 °C | Desktop and office hardware in heated rooms | Industry convention |
| Extended | Often −20 or −25 to 70 °C | Kiosks, signage, light industrial sites | Each vendor |
| Industrial | −40 to 85 °C | Rugged, outdoor and in-vehicle computers | Industry convention |
| Automotive Grade 2 | −40 to 105 °C | Cabin electronics | AEC-Q100 |
| Automotive Grade 1 | −40 to 125 °C | Under-bonnet and engine-bay electronics | AEC-Q100 |
| Military | −55 to 125 °C | Defence and aerospace components | Military specifications |
For components, these figures usually refer to ambient temperature around the part, or sometimes to its case temperature. Processors are more often specified by a maximum junction temperature, the temperature of the silicon itself, which can be 100 °C or more.
Component grade vs system rating
A component grade is not the same as a system rating. Inside a fanless enclosure the board runs hotter than the air around it, so a system built from −40 to 85 °C parts is usually rated to around 70 °C ambient. The 15 °C difference is the heat the system makes itself.
When you specify a system, check three figures on the datasheet:
-
//
Operating temperature. The ambient range the system runs across, measured in the air around the chassis. This is the figure that matters for the installation.
-
//
Storage temperature. The range it survives while switched off, usually wider, for example −40 to 85 °C.
-
//
Conditions of the rating. Whether the top figure assumes airflow, a particular CPU, a certain SSD or a derated workload. Many wide temperature ratings depend on the configuration.
Where the industrial range is needed
Air temperature is only part of the picture. Sun on a metal cabinet, heat from nearby machinery and a lack of airflow can all push the temperature around a computer well above the weather forecast. These are the places where commercial hardware usually struggles.
-
//
Outdoor cabinets. Roadside, trackside and telecom enclosures see frost at night and strong solar heating by day.
-
//
Vehicles. A cab parked in the sun gets far hotter than the outside air, and the same vehicle may have to start on a winter morning.
-
//
Cold stores and freezers. Computers on forklifts or at freezer doors run at −25 °C or below for whole shifts.
-
//
Hot processes. Foundries, kilns, bakeries and engine rooms keep the air around equipment hot all day.
What makes a computer wide temperature
A wide temperature computer is built so the whole system, not only the processor, works across the rated range. Our wide temperature computers combine several design choices:
-
//
Embedded processors. Intel, AMD and Arm embedded parts with industrial temperature options, chosen for heat output that a fanless chassis can shed.
-
//
Industrial memory and storage. Memory and SSDs screened for −40 to 85 °C, since consumer parts often stop at 0 to 70 °C.
-
//
Fanless thermal design. The chassis is the heatsink, so there is no fan to fail in the cold or clog with dust in the heat.
-
//
Cold-start capability. Power circuitry and capacitors that start reliably at the bottom of the range, not only run there once warm.
What happens at the edges of the range
At the hot end, the processor protects itself by throttling: it lowers its clock speed to stay below its junction limit. Our guide to thermal throttling explains how to spot it and design around it. A system that throttles is still working, but at reduced performance, so check the rated temperature at the workload you need.
At the cold end, the risks are different. LCD screens respond slowly, batteries lose capacity and some storage media will not start. Moving from cold to warm can also cause condensation, which our condensation FAQ covers. Our guide to what makes a computer rugged explains the shock, vibration and ingress ratings that usually come with a wide temperature rating, and at board level our rugged single board computers carry the same component grades.
Quick answers on the industrial temperature range
Industrial temperature range: common questions
Is −40 to 85 °C the same as industrial grade?
Yes, for components. It is the usual definition of industrial temperature grade. For complete systems the top figure is usually lower, often 60 to 70 °C ambient.
What is the extended temperature range?
A range between commercial and industrial. There is no single definition. Many vendors use −20 or −25 to 70 °C, so read the datasheet rather than relying on the label.
What is the commercial temperature range?
0 to 70 °C. It covers equipment in heated, air-conditioned rooms. Consumer PCs are often rated narrower again, around 10 to 35 °C ambient.
Is industrial grade the same as military grade?
No. Military-grade components are usually specified to −55 to 125 °C, wider than industrial. A military system also has to meet test standards such as MIL-STD-810.
Can a computer start at −40 °C?
Yes, if it is designed to. Systems rated for cold start use components and power circuits that start at −40 °C. Some add a small heater for the storage or screen.
We supply wide temperature computers built from industrial-grade components and validate each configuration before it ships. Tell us the lowest and highest ambient temperatures on site, and we will specify a system rated for both.