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Converting and Calibrating of the Ohmmeter. 2005 Lab. Purpose: study how to get ammeter range extension; use comparative method to calibrate ammeter and draw calibration curve; comprehensive ammeter’s grade. Devices: electrical source; ammeter; resistor box; rheostat; lead. Principle :.
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Purpose: study how to get ammeter range extension; use comparative method to calibrate ammeter and draw calibration curve; comprehensive ammeter’s grade. • Devices: electrical source; ammeter; resistor box; rheostat; lead.
Principle: Principle: Circuit for a µA-meter modified to a mA-meter by means of range extension
Circuit for modification of a µA-meter to a mA-meter by means of range extension
µA-meter graduation 25.0 20.0 15.0 10.0 5.0 0 Corresponding 10.00 8.00 6.00 4.00 2.00 0 0 Readings of the standard meter Absolute error 0 Data table: Modifying a µA-meter to mA-meter
0 10 20 30 60 90 120 µA-meter’s graduation 25.0 280 360 480 600 1000 2000 3000 µA-meter’s graduation