IEC Industrial platinum resistance thermometers and platinum temperature sensors. The International Standard that specified Industrial PRT’s since has been IEC IEC Ed.2 introduces several significant technical changes with . Buy IEC Ed. Industrial platinum resistance thermometer sensors from SAI Global. STANDARDS. SUBSCRIPTIONS. Content Management Software.

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If you cross reference the temperature you are likely to be measuring and add them to the tolerance standarx the Pt unit you can calculate which Class of probe will be suitable for your application.

People often mistake this for the total accuracy of the system, but that is a mistake! Not only does this informs the user of any adjustments to be made isc the reading at the desired temperature. Temperature is one of the most frequently used parameters in industry, and accuracy in its measurements is critical for the chemical, pharmaceutical, metal, and food sectors.

Minco Components – What is class A and class B tolerance classes for RTDs?

But remember, when specifying a Class A RTD, you must always include the working range at which it must perform to this accuracy. Learn how your comment data is processed. Each probe has the capacity to drift away from this curve reducing accuracy.

How to Mitigate Safety Risks in the Workplace. Kelvin and Rankine, which are absolute temperature scales, and Celsius and Fahrenheit, which are not. These are IEC designations of accuracy. Platinum resistance stanfard are among the most accurate temperature sensors, and are relatively immune to electrical noise, making them particularly well suited for industrial environments. Let’s take the freezing point of water in Celsius for example. To ensure this standrd, the single ice point calibration acceptable for Class B sensors will not suffice.


The IEC therefore states in section 4. As we discussed earlier, you standarx not actually need the accuracy at this point, but rather the repeatability. How to Integrate Demand-driven Planning with Maintenance. The table below shows the tolerances of each Class of probe at various temperatures. The specification was poorly written. Calibration is a fantastic tool for eliminating the known uncertainty that comes with every instrument.

From our previous calculations we know that at the standard calibration temperature points we offer, our own Pt with a Class B probe would normally have the following accuracy uncertainties. Of course, classes A and B or grades A and B cannot cover every possible accuracy specification desired. The International Electrotechnical Commission IEC has published the second edition of its standard on industrial platinum resistance thermometers and platinum temperature sensors. This is not unrealistic for a well-made RTD, although it requires special selection of the sensing element at this temperature.

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Your Pt Thermometer is tested against a known reference standard and a certificate of calibration is produced. Specific changes in the new edition include: Live Temperature Sensor Support.

Pt Accuracy and Probe Classification – ATP Instrumentation Ltd

Specific changes in the new edition include:. The standard specifies 4 classes of accuracy. This one is nice and simple, but often misunderstood.

There are four primary temperature scales in use today. This is the accuracy of the device that actually interprets the signals from the probe and displays your reading. The uncertainty of the unit The uncertainty of the probe Uncertainty of any calibration procedure So lets break it down.


It is more practical to look ied application. Because a well manufactured RTD will have high repeatability relative to the applicationClass B accuracy is generally sufficient unless there is a need for better interchangeability; or when measuring change of temperature; or if you know that you have special accuracy requirements.

The uncertainty of measurement for the thermometer is. Lubricant Storage and Handling.

The class of the probe dictates how much the probe can drift away from this curve. Possible, but not likely.

Subscribe Today Reliable Plant Newsletters. In the examples below we used our own Pt model. This would be displayed as follows this is an example only Calibration Temperature Thermometer Reading This is where thing start to get a little more complex. Toggle navigation Toggle search.

IEC revises standard on thermometers and sensors

If you need to know only, “Is it hot or is it not? Although conforming to the use of a 0. Each probe has a different level of tolerance. But as the temperature increases, so does the permissible deviation due to the variations possible in the TC. The standard also defines the relationship between temperature and the electrical resistance of the thermometer, allowing for the replacement of sensors independent of their manufacturers.

The Best Gets Better: This is the number you will most commonly see listed in product descriptions. Conversely, not all applications require even Class B accuracy.

Hi Santhu, It is just a case of accuracy.