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[Senyaw]

I am running 2 SYL-2352P operating kilns that fire up to 1300degC and both PID's are 100degC out of tolerance eg. when they show 1300 the actual temp inside is 1200, can you explain why this is or how I can rectify it please?

[Kkane]

Do you mean you have 100C off for the display? Do you have another thermometer to monitor your kiln temperature at same time? Does that thermometer have a physical temperature sensor, or it is infrared thermometer?

If you concern about the reading accuracy, you can drop the temperature sensor and your thermometer sensor together in ice/water mixture and boiling water, to compare their reading. If they are reading are good for these two points, the reading should be accuracy for all the range. During the test, the sensor tip must be fully immersed.

It is inaccurate to test the temperature sensor in air, because air has slow response time compared to liquid. In the oven, even you place two sensor side by side, it is very possible to have 100C temperature difference between them. It depends on many factors such as mounting location, sensor type, etc. 

[Senyaw]

Im using cones and an external sensor unit that I pull out a bung, put the rod in and the hand held unit gives me the temp, a 1300degC cone will not tip over until 1400degC and a 1000degC cone will not tip until 1100degC i'm using "R" type thermocouples set on the 'S' setting

[Kkane]

Unfortunately, SYL-2352P doesn't support type R thermocouple. You may need to use a different controller or different type of sensor.

If you use type S setting for type R sensor, there might be some temperature reading error. Because they are different sensor types.

[Senyaw]

Is there that much of a difference between and S and an R, same material just minute percentage differences. Should that cause such a temperature variance?

[Kkane]

Unfortunately, I'm not familiar with type S and type R thermocouple. But based on your provided information, if both controllers have this display error, there is a high chance that this error is not from the controller.

Generally speaking, you can test the whole setup (sensor, sensor cable and controller) with two temperature points, like ice water mixture (32F) and boiling water (~212F). If the reading is accurate for both points, the reading temperature should be accurate for all the reading range. Also, due to the slow response time in the air, it is recommended to test the probe in liquid.

[Senyaw]

Cheers, will do, thank Kkane.