The 7081 voltmeter is a high quality instrument designed for
calibration, laboratory and systems applications. It
combines superb measurement performance with data storage
facilities and processing power. The unit has no internal
options having all facilities as standard.
The instrument provides the following facilities:
• DC voltage and resistance measurements to a scale length
of 140 000 000 and true rms volts ac, or volts ac + dc, to a
scale length of 1400 000.
• The ability to ratio any of the above inputs to a dc
voltage or to a constant.
• Automatic storage of results (History file).
• Processing of measurements to provide additional results.
• Remote control using either RS232C or IEEE-488 (GP-IB)
• Calibration, via either of the two interfaces, without the
need to remove covers.
• Interface for Minate analogue scanner, providing a
multi-channel measurement capability.
DC voltage measurements can be made using scale lengths of
3,4,5,6,7 and 8x9; the 3 and 4x9 scales are available only
by remote control. Each scale length provides a different
integration time and can be used over all ranges, i.e. 0.1
Two types of ac voltage measurement are possible; a true rms
value of the ac component only of an input or the rms of the
total signal (ac + dc). Scale lengths of 3,4,5, and 6x9 and
ranges of 0.1 to 1000V are available for both types of
Ranges of O.1kΩ to lOOOMΩ are provided for resistance
measurement; the 0.1,1,10,100 and lOOOkΩ ranges use a 4
terminal technique whereas the 10 to lOOOMΩ ranges use a
special ratio method. The 7081 also offers a ‘True ohms’
facility, i.e. the unit measures the resistance with the
current source off and then with it on. Subtracting the
former measurement from the latter removes any errors caused
by thermal emfs or external currents. The 7081 ‘True ohms’
facility can deal with emfs of up to 10V.
All measurements taken by the 7081 are averaged readings
over the selected integration time.