User manual

2638A
Users Manual
1-18
AC Current Accuracy
Accuracy is given as ± (% measurement + % of range). Basic accuracy specification is for a sinusoidal signal with
amplitude greater than 5 % of range. For input signals between 1 % to 5 % of range, add 0.1 % of range.
Range Frequency
24 Hour
(23 ±1 °C)
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C Outside
18 °C to 28 °C
100 µA
20 Hz to 2 kHz
0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %
1 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %
10 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %
100 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %
Additional Low Frequency Errors
Error is stated as % of reading.
Frequency
AC Filte
r
20 Hz 200 Hz
20 Hz to 40 Hz
0 %
−
40 Hz to 100 Hz
0 %
0.55 %
100 Hz to 200 Hz
0 %
0.2 %
200 Hz to 1 kHz
0 %
0.02 %
>1 kHz
0 %
0 %
Frequency
Gate Times ............................................................. 100 milliseconds to 1 second.
Measurement Method ........................................... Flexible counting technique. AC-coupled input using the ac voltage
measurement function.
Settling Considerations........................................ When measuring frequency after a dc offset voltage change, errors
may occur. For the most accurate measurement, wait up to 1 second
for the input blocking capacitor to settle.
Measurement Considerations.............................. To minimize measurement errors, shield inputs from external noise
when measuring low-voltage, low-frequency signals.
Frequency Accuracy
Accuracy is given as ± % of measurement.
Range Frequency
24 Hour
(23 ±1 °C)
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C
Outside 18
°C to 28 °C
100 mV to
300 V
[1] [2]
20 Hz to 40 Hz 0.03 % 0.03 % 0.03 % 0.001 %
40 Hz to 1 MHz
0.006 % 0.01 % 0.01 % 0.001 %
[1] Input >100 mV. For 10 mV to 100 mV, multiply percent measurement error by 10.
[2] Limited to 3 x 10
7
volt-Hertz
Resistance
Measurement Method ........................................... Current source referenced to LO input.
Max. Lead Resistance (4-wire ohms) .................. 10 Ω per lead for 100 Ω, 1 kΩ ranges. 1 kΩ per lead on all other
ranges.
Input Protection .................................................... 300 V on all ranges.