69. The LX-PA-50 (Unimeasure) is a linear position sensor based on a potentiometer that can measure displacements from 0 m to 1.25 m, and that has 10.25 %FSO linearity (FSO: full scale output), "1000 + 15%" resistance, 25 V maximal excitation voltage, and + 0.0025 %FSO/C temperature coefficient. If its output voltage is digitized by an ADC whose voltage reference is the same used to excite the potentiometer determine: a) The number of bits of the ADC so that its resolution is smaller than the uncertainty of the sensor? A: N= 8 bit. b) The digital output (in natural binary code) when the input is 0.5 m and If N = 12 bit. A: D = 1638, 0110 0110 0110. c) The displacement (value and uncertainty) when the ADC output is 1000 1000 1000. A: x = 0.666 m + 3 mm. d) The minimal value for the input resistance of the ADC for the voltage loading effect to be negligible when the wiper is at its central position. A: R>1.1 M 2. e) The maximal temperature change with respect to the calibration temperature for that change not to affect the digital output. A: 5 C. Since we only need 8 bits, it would be better no to display the four less significant bits of the ADC. 69. The LX-PA-50 (Unimeasure) is a linear position sensor based on a potentiometer that can measure displacements from 0 m to 1.25 m, and that has 10.25 %FSO linearity (FSO: full scale output), "1000 + 15%" resistance, 25 V maximal excitation voltage, and + 0.0025 %FSO/C temperature coefficient. If its output voltage is digitized by an ADC whose voltage reference is the same used to excite the potentiometer determine: a) The number of bits of the ADC so that its resolution is smaller than the uncertainty of the sensor? A: N= 8 bit. b) The digital output (in natural binary code) when the input is 0.5 m and If N = 12 bit. A: D = 1638, 0110 0110 0110. c) The displacement (value and uncertainty) when the ADC output is 1000 1000 1000. A: x = 0.666 m + 3 mm. d) The minimal value for the input resistance of the ADC for the voltage loading effect to be negligible when the wiper is at its central position. A: R>1.1 M 2. e) The maximal temperature change with respect to the calibration temperature for that change not to affect the digital output. A: 5 C. Since we only need 8 bits, it would be better no to display the four less significant bits of the ADC