Our DCS RTD module supports only PT100 and JPT100, but we need to connect RTD type PT110 and PT10 available in the existing plant to the DCS RTD module. Can you suggest suitable method for connecting to DCS RTD module? optionally, DCS module supports POT i/p.

 

If your existing analog input module does not support either
- your types of RTDs, or
- generic resistance measurement that can be either converted to a 4-20mA/Profibus/FoundationFieldbus signal and then

characterized/linearized/function-generated/look-up-tabled in the DCS or
characterized/linearized/function-generated/look-up-tabled in the transmitter itself

then you'll have to look for a temperature transmitter that is designed to take a variable resistance on its input and then
characterized/linearized/function-generated/look-up-tabled in the DCS or
characterized/linearized/function-generated/look-up-tabled in the transmitter itself

For example, Siemens TH300 transmitter has two options, an internal X-Y linearizer/characterizer table or a scaling function.

Siemens PDM software is needed to access the X-Y linearization tables, which are hidden as the choice "User Defined Curve" rather than "linear", the default selection that is displayed.

I seem to recall that it defaults to 5 X-Y pairs, but can be expanded to more pairs. There's an odd term, like 'number of X-Y terms, or pairs, or couples or something like that.

The scaling factor is disguised by the term "number of sensors", a 3 digit value to 2 decimal places, like 1.25 or 0.93. The term is confusing because sensors are never 'partial' sensors, sensors are whole sensors. The term refers to the scaling factor, a multiplier/divisor factor.

An example I saw somewhere stated that to use a Pt1000 sensor the sensor type was selected as Pt100, and the number of sensors was declared to be 10.0.

I've never used the functions, but the odd terminology amused me so I recalled it.

You might want to confirm that the 10 ohm RTD is truly platinum (Pt) and not Cu (copper) and that the 110 ohm RTD is not really a 120 ohm nickel RTD.