Basic Knowledge

What is the difference between PT100 PT1000 and PT500 ?

2022-12-19 07:58:55 admin 3

This number 100,500,1000 refers to the reference resistance of the Rtd.meaning pt 100 means at 0 degree temp it gives 100 ohm resistance,similarly pt 500 gives, 500 ohm resistance at 0 degree.but now questions arrise why we go for higher resistance and the ans is simple: for good sensitivity and accuracy.

Distinction between Pt100 and Pt1000

The Pt100 has lower resistance and is suited for three and four-wire circuit configurations. On the other hand, the Pt1000 is suitable for two-wire circuit configurations. As the Pt100 sensors have less resistance, the resistance from the lead wires has a higher distorting effect on the overall resistance of the circuit. The Pt1000’s higher resistance makes the distorting effect of the resistance in the lead wires less significant overall.

The ohmic value distinguishes the two in their name. The ohmic value at 0°C for Pt100 is 100 Ω. At 0°C, the ohmic value for Pt1000 is 1000 Ω. The Pt1000 also works better for applications running on battery power than the Pt100. It makes the Pt1000 have fewer inaccuracies.

There is also a difference in their element constructions. Pt1000s are only available with thin-film element constructions, whereas Pt100 has a thin-film or a wire-wound element construction. It is essential to note that the output for the Pt1000 is high, making it more accurate.

The main difference between the two sensors is their nominal resistance. It influences the decision on which model to use. The output resolution is higher in Pt1000 by a factor of 10 due to the nominal resistance difference. The difference is most notable when comparing the two-wire configurations that give lead measurement errors as applicable.

Pt100 or Pt1000?

The decision on which models to select relies on some factors and their application. However, the Pt100 sensor is generally popular due to the following reasons:

Pt100 sensors are available in both thin film constructions and wire wounds. It provides more choices and flexibility compared to Pt1000s which do not have both options.

Pt100s suits several instruments and processes hence more utility when acquiring it

There are instances where one would prefer the Pt1000 over the Pt100. It is notable due to its superiority over Pt100 in particular circumstances. These include:

The Pt1000 sensor is superior in 2-wire configurations under conditions where extended lead wires are used. Fewer wires exhibit higher resistance and fewer inaccuracies. The sensor has nominal resistance that makes amends for the inaccuracies.

Pt1000 sensors are more suitable for applications powered by a battery as they require less power to operate.

Pt1000 sensors are less self-heating.

So what is the difference between a Pt100 and a Pt1000?

The aspects of the application will determine whether to use Pt100 or Pt1000. The number of wires also influences your choice depending on whether you use 2, 3, or 4 wires. The platinum resistance thermometers get their difference in their name which expresses their electrical resistance. Generally, Pt100 sensors are often used in industrial processes and laboratories. Pt1000 sensors are applied in heating, ventilation, refrigeration, machine building, and automation.