Question

Suppose we include the lead resistance in the calculation of temperature for a class A RTD. If R3 = 1000 ohms, Ra = 18 ohms, V0 = 1.80 volts, and V = 5 volts. Including the tolerances, what is the highest temperature you could measure in °C? (Type in a two-decimal number)

Answer 1

Answer:

The highest temperature that could be measured(in °C) is 14170.27°C

Explanation:

RTDs are thermometers consist metals of which it resistance increase with temperature.

For Class A RTD l,Alpha = 0.00385.

The formula for RTD is

Rt = Ro ( 1 + alpha x t)

Where

Rt is Resistance at temperature t°C,

Ro is the Resistance at 0°C

Alpha is a constant temperature coefficient of class A RTD.

Here, Rt = 1000ohms,

Ro is taking as Ra = 18Ohms

Therefore,

1000 = 18 ( 1 + 0.00385t)

Divide both sides by 18

1 + 0.00385t = 1000/18

0.00385t = 55.55 - 1

0.00385t = 54.55

t = 54.55/0.00385

t = 14170.27°C