- A An Accelerometer Is An Electromechanical Device That Measures Acceleration Forces Including Static And Dynamic The M 1 (72.16 KiB) Viewed 27 times
- A An Accelerometer Is An Electromechanical Device That Measures Acceleration Forces Including Static And Dynamic The M 2 (48.93 KiB) Viewed 27 times
a) An accelerometer is an electromechanical device that measures acceleration forces including static and dynamic. The most common type of accelerometer is a piezoelectric accelerometer. Table 1 shows the performance sheet of a few models of accelerometer available in the market. i) Discuss the basic mechanism of an accelerometer. [7 Marks] [CO1, PO1, C4] ii) As an engineer, you need to find an accelerometer for a vibration analysis of a centrifugal pump which operates with maximum 100 Hz. Assess which one is the recommended accelerometer based on Table 1 and justify your answer. 15 Marks] [CO1, P01, C5] iii) A quartz crystal having a thickness of 1.5 mm is subjected to a pressure of 55 psi. Find the output voltage if the voltage sensitivity is 0.055 V-m/N. MODEL NUMBER UNITS 2210-002 2210-005 2210-010 2210-025 2210-050 2210-100 2210-200 2210-400 Input Range +2 +5 +10 +25 Table 1 +50 +100 +200 +400 Frequency Response (Nominal, 3 dB) Hz 0-300 0-400 0-600 0-1000 0-1500 0-2000 0-2500 0-3000 [5 Marks] [CO1, PO1, C3] Sensitivity, Differential mV/g 2000 800 400 160 80 40 20 10
b) A linear variable displacement transducer (LVDT) senses displacement and indicates a voltage output, which is linear to the input. Figure 1 shows an LVDT setup used for static calibration. It uses a micrometre to apply the known displacement and a voltmeter for the output. i) Suggest the independent, dependent and extraneous variables in this calibration. [4 Marks] [C01, PO1, C4] ii) Indicate the basic functional elements of the device in Figure 1 in the form of block diagram. 0 Micrometer Fixed mounts Connector Excitation voltage in Figure 1 Primary coll LVDT Output voltage 10.135 Voltmeter [4 Marks] [CO1, PO1, C3] Secondary coil Core