CC-PAIX02 51405038-475 Temperature Sensor

CC-PAIX02 51405038-475 For this test system, a group of Pt resistance temperature sensors under test is first placed in an ice-water mixture to measure the voltage value at both ends of this group of Pt resistors at 0°C, and then this group of Pt resistance temperature sensors is placed in a liquid medium at 100°C to measure the voltage value at both ends of this group of Pt resistors at 100°C. The A/D input voltage used in this test system is between 0V and 138Ω at 0°C, while the A/D input voltage used in this test system is between 0V and 100W. The measured temperature sensor Pt100 in 0 ℃ resistance value of 100W, in 100 ℃ resistance value of 138 Ω. And this test system used in the A/D input voltage in the 0V ~ 2.5 V. This system of constant current source current is set at 0.5mA.

CC-PAIX02 51405038-475 The four-wire wiring method used to test the Pt temperature sensor eliminates errors caused by long wires. The equivalent form of the Ptn is shown in Fig. 1, where Rn1, Rn2, Rn3 and Rn4 are the lead and contact resistors and have the same resistance value.Rn1 and Rn2 are the lead resistors of the voltage detection circuit, and Rn3 and Rn4 are the lead resistors of the constant current source circuit. This circuit in the measurement of voltage, by Rn1 and Rn2 voltage drop caused by the measurement error, far less than the value of the voltage across the Pt resistance temperature sensor, negligible, Rn3 and Rn4 because it is connected in series with the constant-current source, so it can also be ignored.

The electronic switch of CC-PAIX02 51405038-475 adopts an eight-option CMOS analogue switch CD4051, whose resistance is about a few hundred ohms when it is on, but we can regard the on-resistance of Ka as a part of the differential-mode input impedance of the op-amp in the constant-current source circuit, and the on-resistance of Kb can be regarded as a part of the input impedance of the op-amp in the amplifier circuit, so γ3≈ 0. 0 . According to the characteristics of CC-PAIX02 51405038-475, the input offset voltage is 0.5μV~1μV; the offset voltage drift is 0.003μV/ oC; assuming that the temperature change of the system working environment ΔT=10℃, the error of the amplifier circuit γ4 can be calculated.