Datasheet
7 Fluke Corporation 2638A Hydra Series III Data Acquisition System/Digital Multimeter
Measurement specifications
Accuracy specifications generally are valid for 6.5
digit resolution mode (unless otherwise noted)
after a minimum of one-hour warm-up, and
within an operating temperature range of 18 °C
to 28 °C. Derating applies with a fast sample rate
and for operating temperatures outside the limited
range. Twenty-four-hour specifications are relative
to calibration standards and assume a controlled
electromagnetic environment per EN 61326. The
confidence level for accuracy specifications is
95 % within one year of calibration (unless other-
wise noted).
Measurement specifications
Scan rate
Fast
45 channels per second max (0.03 seconds per channel, depending on function
and range)
Medium 16 channels per second (0.1 seconds per channel)
Slow 2 channels per second (0.5 seconds per channel)
Custom Selectable from 0.2 NPLC to 200 NPLC
Display resolution 4.5 to 6.5 digits, depending on function and sample rate
Specifications
DC voltage
Maximum input 300 V
Common mode rejection 140 db at 50 Hz or 60 Hz ±0.1 % (1k Ω imbalance)
Normal mode rejection 60 db for NPLC of 1 or greater and power-line frequency ±0.1 %
Measurement method Multi-ramp A/D
A/D linearity 2 ppm of measurement + 1 ppm of range
Input bias current 30 pA at 25 °C
DC voltage input characteristics
Range Resolution
Measurement rate/Resolution
Input impedance
Fast 4.5 digits Medium 5.5 digits Slow 6.5 digits
100 mV 100.0000 mV 10 µV 1 µV 0.1 µV 10 MΩ or >10 GΩ
[1]
1 V 1.000000 V 100 µV 10 µV 1 µV 10 MΩ or >10 GΩ
[1]
10 V 10.00000 V 1 mV 100 µV 10 µV 10 MΩ or >10 GΩ
[1]
100 V 100.0000 V 10 mV 1 mV 100 µV 10 MΩ ±1 %
300 V 300.000 V 100 mV 10 mV 1 mV 10 MΩ ±1 %
[1] 10 MΩ is default input impedance.
DC voltage accuracy
Accuracy is given as ± (% measurement + % of range).
Range 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 0.0025 + 0.003 0.0025 + 0.0035 0.0037 + 0.0035 0.0005 + 0.0005
1 V 0.0018 + 0.0006 0.0018 + 0.0007 0.0025 + 0.0007 0.0005 + 0.0001
10 V 0.0013 + 0.0004 0.0018 + 0.0005 0.0024 + 0.0005 0.0005 + 0.0001
100 V 0.0018 + 0.0006 0.0027 + 0.0006 0.0038 + 0.0006 0.0005 + 0.0001
300 V 0.0018 + 0.002 0.0031 + 0.002 0.0041 + 0.002 0.0005 + 0.0003