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Digital Multimeter

8½-digit high-precision and high-accuracy digital multimeter for system calibration

The 7481 is an 8½-digit digital multimeter with high resolution of 0.01 ppm. It is suitable for use in research and development fields or calibration organizations, and calibration of inspection systems for electronic components or semiconductors. The 7481 achieves high-resolution measurement such as 10 nV for DC voltage measurement, 100 fA for DC current measurement and 1 μΩ for resistance measurement, and also guarantees high relative accuracy 5 ppm per year for voltage measurement.
In addition, the self-calibration function allows high-accuracy measurement at any time, and external calibration can be performed with a smaller number of standards. The 7481 has not only the GPIB and the USB as interface for automatic systems but also input terminals on the rear panel for easy system configuration.


High-accuracy digital multimeter equipped with simple calibration function

  DC voltage Resistance DC current DC voltage ratio
Maximum display  119 999 999 119 999 999  11 999 999   99 999 999
Relative accuracy* 0.5+0.1 2+0.2  5+10  1.25+0.25 
Condition  10 V range 10 kΩ range  1000 μA range  10 V range

*Relative accuracy: ppm of reading ± ppm of range, 23°C ± 1°C, 24 hours

All you need to perform external calibration for the 7481 are two sources: a DC voltage standard (10 V) and a resistance standard (10 kΩ). By the two-source calibration and the self-calibration function, all rages of DC voltage, DC current and resistance are calibrated and internal errors due to ambient temperature change can be removed. As a result, high-accuracy measurements are guaranteed. Calibration values are stored in the internal memory together with its calibration date, and these data can be read out by the GPIB or USB.

High-precision A/D converter
The 7481 adopts a self-developed multi-scope integration system for A/D conversion. So, it realizes high-precision linearity and excellent stability as standard, making it possible to perform high-accuracy measurements.

Low-noise design
The 7481 offers measurement with less dispersion by its low-noise ranging amplifier. 

Ratio measurement function 
In ratio measurement, the reference DC voltage is measured by using the 4 WΩ measurement terminal in addition to normal DC voltage measurement, and its voltage ratio is gained by calculation. Using this function, it is possible to measure attenuator voltage division ratio and electric power, eliminating error factors of the external supply source in resistance measurement.

Various functions convenient for measurements

  • 50,000 data internal memor
  • Front/rear input terminal external control 
  • 4-wire contact check function
  • Comparator function
Maximum display 119 999 999
DC voltage measurement 10 nV to 1000 V
Accuracy (typical value) 5 ppm/year
DC current measurement 100 fA to 1 A
Resistance measurement 1 μΩ to 1000 MΩ
AC voltage measurement (True RMS) N/A
AC current measurement (True RMS) N/A
Calculation function
Temperature measurement
Data memory 50,000
Interface GPIB , USB

*For the detailed specifications, please download the brochure from "Documents."