Fluke 45 - Page 21

Introduction and Specifications
Specifications
1
1-9
Input Impedance
1 MΩ in parallel with <100 pF
Maximum Crest Factor
3.0
Common Mode Rejection Ratio
>60 dB at 50 or 60 Hz (1 kΩ unbalanced medium rate)
Maximum Input
750 V rms, 1000 V peak
2 x 10
7
Volt-Hertz product on any range, normal mode input
1 x 10
6
Volt-Hertz product on any range, common mode input
(AC + DC) Voltage Accuracy
Total Measurement Error will not exceed the sum of the separate ac and dc accuracy
specifications, plus 1 display count. Refer to the table under "Maximum Allowable AC
Voltage While Measuring DC Voltage or (AC + DC) Voltage" located on page 1-6.
Note
When measuring AC + DC, (or any dual display combination of AC and
DC) in the fast reading rate, the Fluke 45 may show significant reading
errors. This results from a lack of filtering on the DC portion of the
measurement for the fast reading rate. To avoid this problem, use only the
"slow" and "medium" reading rates for AC + DC or AC and DC
combinations.
Maximum Frequency of AC Voltage Input While Measuring AC Current
When the meter makes ac current and ac voltage measurements using the dual display,
the maximum frequency of the voltage input is limited to the maximum frequency of the
current function. For example, if you are making an ac current measurement on the 10 A
range, the maximum frequency of the voltage input must be less than 2 kHz.
DC Current
Range
Resolution
Burden
Slow Medium Fast Accuracy
Voltage*
30 mA - 1 µA 10 µA 0.05% + 3 0.45 V
100 mA - 10 µA 100 µA 0.05% + 2 1.4 V
10 A - 1 mA 10 mA 0.2% + 5 0.25 V
10 mA 100 nA - - .05% + 15 0.14 V
100 mA 1 µA - - 0.05% + 5 1.4 V
10 A 100 µA - - 0.2% + 7 0.25 V
*Typical at full range