7451A/7461A/7461P Digital Multimeter Operation Manual
7.1.3 Resistance Measurement (2W, LP-2W, 4W, LP-4W)
7-8
Additional error depending on the integration time
Voltage between input terminals without connections.9.5 V or less
Maximum allowable applied voltage
• 7451A
2W and 4W measurements
Integration time Additional error (digit + m)
10 s IT 200 s - In a 3 1/2-digit display 2+20
200 s < IT 2 ms Includes FAST1 and FAST2. In a 4 1/2-digit display 2+20
2 ms <IT < 1 PLC - In a 5 1/2-digit display 2+20
1 PLC IT < 10 PLC Integral multiple of 1 PLC In a 6 1/2-digit display 1+0
10 PLC < IT 10 s Integral multiple of 1 PLC In a 6 1/2-digit display 2+0
Between and COM 1000 Vpeak
Between COM and the chassis 500 V
Between 4WHi-4WLo 200 Vpeak
Between 4WHi, 4WLo and the chassis 500 V
Range
Maximum
display
Resolution
Measurement
current
Measurement accuracy *1
(% of reading + digits)
Temperature coefficient *5
(ppm of reading + digits)/C
24 hours
23C 1C *2
90 days
23C 5C
1 year
23C 5C
Auto-zero
ON
Auto-zero
OFF
30 31.9999 100 10 mA 0.0030+30.0 0.0100+40.0 0.0150+40.0 10.0+5.0 10.0+50.0
300 319.999 1 m 1 mA 0.0020+5.0 0.0080+11.0 0.0150+11.0 10.0+1.0 10.0+6.0
3000 3199.99 10 m 1 mA 0.0020+3.0 0.0070+3.0 0.0120+3.0 10.0+0.2 10.0+3.0
30 k 31.9999 100 m 100 A 0.0020+3.0 0.0070+3.0 0.0130+3.0 10.0+0.2 10.0+3.0
300 k 319.999 1 10 A 0.0020+3.0 0.0090+3.0 0.0140+3.0 8.0+0.2 8.0+3.0
3000 k 3199.99 10 1 A 0.0070+14.0 0.0300+19.0 0.0300+19.0 35.0+5.0 35.0+5.0
30 M 31.9999 100 100 nA 0.0600+14.0 0.1800+19.0 0.2000+19.0 100.0+5.0 *3 100.0+5.0 *3
300 M 319.999 1 k 10 nA 0.6000+14.0 1.7000+19.0 2.0000+19.0 1000.0+5.0 *4 1000.0+5.0 *4
*1 Integration time: 10 PLC, Auto-zero: ON for 2W, Display digit: 5 1/2
The measurement cable resistance and 0.2 (internal circuit resistance error) are added to the digit error in 2W measurement.
*2 Relative value with respect to the calibration standard
*3 115 ppm/C is added to the temperature coefficient in the temperature range of 30
C to 50C.
*4 1150 ppm/C is added to the temperature coefficient in the temperature range of 30C to 50C.
*5 The temperature coefficient in Auto-zero ON is used in the 4W measurement.