Step 4: For 2-line measurements, the Auto Zero soft key is available. Auto Zero : Auto Zero: Auto Zero provides the most accurate measured value but requires additional time to perform the reset-to-zero measurement. With Auto Zero enabled (ON), the DMM makes an internal measurement of the offset after each measurement and then the offset value is subtracted from the previous reading. This prevents the offset voltage on the DMM input circuit from affecting the measurement accuracy. With Auto Zero disabled (OFF), the DMM makes a measurement of the offset and subtracts the offset from all subsequent measured parameters. Step 5:
Press Aperture and select the number of power cord circulation (PLC) for measurement. Only 1, 10 and 100 PLCs provide normal mode (line frequency noise) suppression.Choose 100 PLC to provide the best noise suppression and resolution, but the slowest measurement speed: Step 6: Use the Units soft key to display the Celsius, Fahrenheit, or Kelvin temperature. Temperature measurements require a temperature transducer probe. The supported probes are 2-wire and 4-wire RTDs, 2-wire and 4-wire thermistors (5k 44007 type). Probe Type Choice RTD's provide very accurate, highly linear relationships between resistance and temperature, over a range of roughly –200 to 500 °C.
There is very little conversion complexity for an RTD because it is so intrinsically linear. Thermistors consist of semiconductor materials, and provide roughly ten times the sensitivity of the RTD. Because they are semiconductors, their temperature range is more limited, commonly to –80 to 150 °C. Thermistors have highly non–linear temperature–resistance relationships; therefore their conversion algorithms are more complex. Important: Use only a 5 kΩ 44007-type thermistor. This type thermistor has constants of A = 1.285e-3, B = 2.362e-4, C = 9.285e-8. Using an incorrect type of thermistor can result in errors greater than 20 °C for a temperature being measured of 100 °C.
The capacitance This section describes how to configure capacitance measurements from the front panel. 37