Agilent Technologies 34970A manual = − GF x R

Chapter 4 Features and Functions

Mx+B Scaling

•During a Monitor operation, the gain and offset values are applied to all readings on the specified channel.

•You can specify a custom label with up to three characters. You can

use letters (A-Z), numbers (0-9), an underscore ( _ ), or the “#” character which displays a degree symbol ( ° ) on the front panel (displayed as a blank space in an output string from the remote interface). The first character must be a letter or the “#” character (the “#” character is allowed only as the leftmost character in the label). The remaining two characters can be letters, numbers, or an underscore.

Note: If you set the measurement label to °C, °F, or K, note that this has no effect on the temperature units set in the Measure menu.

•Although the instrument does not directly support strain gage measurements, you can measure a strain gage using a 4-wire resistance measurement with scaling. For more information, refer to “Strain Gage Measurements” on page 373.

Note: Agilent BenchLink Data Logger software has built-in strain gage measurement capability.

Use the following equations to calculate the gain and offset.

M =	1	B = −	1
	GF x R0		GF

Where GF is the gage factor and R0 is the unstrained gage resistance. For example, a 350Ω strain gage with a gage factor of 2 would use the following gain and offset values: M=0.001428571, B=-0.5 (be sure to use 61⁄2 digits of resolution for this measurement).

•The maximum gain allowed is ±1E+15 and the maximum offset allowed is ±1E+15.

•The MEASure? and CONFigure commands automatically set the gain (“M”) to 1 and offset (“B”) to 0.

•A Factory Reset (*RST command) turns off scaling and clears the scaling values on all channels. An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not clear the scaling values and does not turn off scaling.

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