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2638A
HYDRA Series III Data Acquisition Unit
August 2014 Rev. 1, 5/16
© 2014-2016 Fluke Corporation. All rights reserved. Specifications are subject to change without notice.
All product names are trademarks of their respective companies.
Calibration Manual
Table of Contents
Title Page
Introduction ............................................................................................ 1
Contact Flu
Safety Information ................................................................................. 2
General Specifications .......................................................................... 5
Measurement Specifications ................................................................. 6
DC Voltage ........................................................................................ 6
DC Voltage Input Characteristics .................................................. 6
DC Voltage Accuracy .................................................................... 7
DC Voltage Additional Errors ......................................................... 7
AC Voltage ........................................................................................ 7
AC Voltage Input Characteristics ................................................... 8
AC Voltage Accuracy ..................................................................... 8
Additional Low Frequency Errors ...................................................... 8
DC Current ........................................................................................ 8
DC Current Input Characteristics ................................................... 9
DC Current Accuracy ..................................................................... 9
DC Current Additional Errors ......................................................... 9
AC Current ......................................................................................... 9
AC Current Input Characteristics ................................................... 9
AC Current Accuracy ..................................................................... 10
Additional Low Frequency Errors ...................................................... 10
Frequency .......................................................................................... 10
Resistance ......................................................................................... 10
Resistance Input Characteristics ................................................... 11
Resistance Accuracy ..................................................................... 11
Resistance Additional Errors ......................................................... 11
RTD ................................................................................................... 11
RTD Temperature Accuracy .......................................................... 12
RTD Measurement Characteristics ............................................... 12
Thermistor ......................................................................................... 12
Thermistor Temperature Accuracy ................................................ 12
Thermistor Measurement Characteristics ...................................... 13
Thermocouple .................................................................................... 13
Thermocouple Temperature Accuracy .......................................... 13
Thermocouple Measurement Characteristics ................................ 14
Digital I/O ........................................................................................... 14
ke ........................................................................................ 1
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2638A
Calibration Manual
Totalizer ............................................................................................. 14
Trigger ............................................................................................... 15
Alarm Output ..................................................................................... 15
2638A-100 Universal Input Module ....................................................... 15
General Maintenance ............................................................................ 16
If the Product Does Not Turn On ....................................................... 16
Clean the Product .............................................................................. 16
Replace the Line Power Fuse ........................................................... 16
Battery Replacement ......................................................................... 17
Memory and Factory Reset ............................................................... 18
Required Equipment .............................................................................. 19
Test Considerations .............................................................................. 21
Performance Tests ................................................................................ 21
Front Panel Test ................................................................................ 22
DC Volts Verification .......................................................................... 22
Volts AC and Frequency Verification ................................................. 24
4-Wire Ohms Verification ................................................................... 26
PRT Verification Steps ...................................................................... 27
Configure Resistance Display ........................................................... 27
Thermistor Verification Steps ............................................................ 28
Configure Resistance Display ........................................................... 28
DC Current Verification ...................................................................... 29
AC Current Verification Steps ............................................................ 31
2638A-100 Module Verification ......................................................... 32
Calibration Adjustment .......................................................................... 33
Unlock the Product ............................................................................ 33
Unlock the Product with a Remote Interface ..................................... 33
Reset the Admin Password ............................................................... 34
Disassembly ...................................................................................... 35
Change the Calibration Date Remotely ............................................. 37
“Mainframe” Adjustment Process ...................................................... 37
Remote Commands for Calibration ....................................................... 43
Remote Programming Examples ....................................................... 44
Start a Full Calibration ....................................................................... 44
Calibrate 1 V DC Range only ............................................................ 45
Write Calibration Date to a Module .................................................... 45
Command References ....................................................................... 46
User-Replaceable Parts and Accessories ............................................. 51
ii
Introduction
The Fluke 2638A HYDRA Series III Data Acquisition Unit (the Product or
Instrument) is a 67 analog channel bench-top data logger that measures and
records dc volts, ac volts, dc current, ac current, resistance, frequency, and
temperature. See the Specifications section for information on the types and
ranges of the measurement inputs the Product can accept.
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Safety Information
Symbol Description Symbol Description
A Warning identifies conditions and procedures that are dangerous to the user.
A Caution identifies conditions and procedures that can cause damage to the
Product or the equipment under test.
See Table 1 for a list of symbols used in this manual and on the Product.
Table 1. Symbols
W
X
or
Ã
~
Risk of Danger. Important
information. See Manual.
Hazardous voltage. Voltage
>30 V dc or ac peak might be
present.
Earth ground. Digital signal
AC or DC (Alternating or Direct
Current)
Recycle.
Conforms to relevant South
Korean EMC Standards.
Measurement Category II is applicable to test and measuring circuits connected directly to
utilization points (socket outlets and similar points) of the low-voltage MAINS installation.
Measurement Category III is applicable to test and measuring circuits connected to the
distribution part of the building’s low-voltage MAINS installation.
Measurement Category IV is applicable to test and measuring circuits connected at the
source of the building’s low-voltage MAINS installation.
This product complies with the WEEE Directive marking requirements. The affixed label
indicates that you must not discard this electrical/electronic product in domestic household
waste. Product Category: With reference to the equipment types in the WEEE Directive
Annex I, this product is classed as category 9 "Monitoring and Control Instrumentation”
product. Do not dispose of this product as unsorted municipal waste.
DC (Direct Current)
AC or DC (Alternating or Direct Current)
T
+
Double insulated
Power ON / OFF
P Conforms to European Union directives.
2
HYDRA Series III Data Acquisition Unit
Safety Information
WXWarning
To prevent possible electrical shock, fire, or personal injury:
• Read all safety information before you use the Product.
• Carefully read all instructions.
• Use the Product only as specified, or the protection supplied
by the Product can be compromised.
• Examine the case before you use the Product. Look for cracks
or missing plastic. Carefully look at the insulation around the
terminals.
• Do not use the Product if it operates incorrectly.
• Do not use the Product if it is damaged.
• Disable the Product if it is damaged.
• Use only the mains power cord and connector approved for
the voltage and plug configuration in your country and rated
for the Product.
• Replace the mains power cord if the insulation is damaged or
if the insulation shows signs of wear.
• Make sure the ground conductor in the mains power cord is
connected to a protective earth ground. Disruption of the
protective earth could put voltage on the chassis that could
cause death.
• Do not put the Product where access to the mains power cord
is blocked.
• Use only correct measurement category (CAT), voltage, and
amperage rated probes, test leads, and adapters for the
measurement.
• Use only cables with correct voltage ratings.
• Do not use test leads if they are damaged. Examine the test
leads for damaged insulation and measure a known voltage.
• Do not exceed the Measurement Category (CAT) rating of the
lowest rated individual component of a Product, probe, or
accessory.
• Keep fingers behind the finger guards on the probes.
• Do not apply more than the rated voltage, between the
terminals or between each terminal and earth ground.
• Do not touch voltages >30 V ac rms, 42 V ac peak, or 60 V dc.
• Limit operation to the specified measurement category,
voltage, or amperage ratings.
• Measure a known voltage first to make sure that the Product
operates correctly.
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2638A
Calibration Manual
• Consider all accessible channels to be hazardous live and an
electric shock hazard if any channel is connected to a
hazardous voltage source.
• Do not remove, touch, or change the internal wiring of
hazardous inputs until the input source is turned off.
• Remove inputs from hazardous voltage sources before an
input module is opened.
• Use the correct terminals, function, and range for
measurements.
• Use this Product indoors only.
• Do not use the Product around explosive gas, vapor, or in
damp or wet environments.
4
HYDRA Series III Data Acquisition Unit
General Specifications
General Specifications
Mains Voltage
100 V Setting ...................................................... 90 V to 110 V
120 V Setting ...................................................... 108 V to 132 V
220 V Setting ...................................................... 198 V to 242 V
240 V Setting ...................................................... 216 V to 264 V
Frequency .............................................................. 47 Hz to 440 Hz
Power Consumption ............................................. 36 VA peak (24 W average)
Environment Temperature
Operating ............................................................ 0 °C to 50 °C
Full accuracy ....................................................... 18 °C to 28 °C
Storage ............................................................... -20 °C to 70 °C
Warm-up ............................................................. 1 hour to full accuracy specifications
Relative Humidity (non-condensing)
Operating ............................................................ 0 °C to 28 °C <90 %
28 °C to 40 °C <75 %
40 °C to 50 °C <45 %
Storage ............................................................... -20 °C to 70 °C <95 %
Altitude
Operating ............................................................ 2,000 m
Storage ............................................................... 12,000 m
Channel Capacity
Total analog channels ........................................ 67
Voltage/resistance channels ............................... 61
Current channels ................................................ 7
Digital I/O ............................................................ 8 bits
Totalizer .............................................................. 1
Alarm outputs...................................................... 6
Trigger input ........................................................ 1
Channel Capacity: 2638A/05
Total analog channels ......................................... 23
Voltage/resistance channels ............................... 21
Current channels ................................................ 2
Safety Protection
Mains Input ......................................................... IEC 61010-1, Overvoltage Category II, Pollution Degree 2
Measurement Front Panel .................................. IEC 61010-2-030: CAT II 300 V
Measurement Rear Panel ................................... IEC 61010-2-030: CAT II 150 V CAT II, 250 V rms with maximum
Electromagnetic Compatibility (EMC)
International ........................................................ IEC 61326-1: Basic Electromagnetic Environment
transient voltage of 1000 V peak. These terminals are not intended for
connection to mains voltage above 150 V without external transient
suppression. The maximum input that can be applied between rearmodule terminals or between any rear-module terminal and earth
ground is 250 V dc or ac rms.
CISPR 11: Group 1, Class A
Group 1: Equipment has intentionally generated and/or uses
conductively-coupled radio frequency energy that is necessary for
the internal function of the equipment itself.
Class A: Equipment is suitable for use in all establishments other
than domestic and those directly connected to a low-voltage power
supply network that supplies buildings used for domestic purposes.
There may be potential difficulties in ensuring electromagnetic
compatibility in other environments due to conducted and radiated
disturbances.
Emissions that exceed the levels required by CISPR 11 can occur
when the equipment is connected to a test object.
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2638A
Calibration Manual
Korea (KCC) ....................................................... Class A Equipment (Industrial Broadcasting & Communication
USA (FCC) .......................................................... 47 CFR 15 subpart B. This product is considered an exempt device per
Math Channels
Number of channels............................................ 20
Operations .......................................................... sum, difference, multiply, divide, polynomial, power, square root,
Triggers .................................................................. interval, external (trigger input), alarm, remote (bus), manual
Battery life ............................................................. 5 years
Memory
Scan data RAM................................................... 75,000 readings with timestamp
Data/Setup flash memory ................................... 20 MB
Non-volatile memory life ..................................... 5 years
USB Host Port
Standard ............................................................. 2.0, full speed
Connector type ................................................... Type A
Function .............................................................. Memory
File system .......................................................... FAT32
Memory capacity................................................. 32 GB
USB Device Port
Connector type ................................................... Type B
Class ................................................................... Instrument
Function .............................................................. Control and data transfer
Command protocol ............................................. SCPI
LAN
Function .............................................................. Control and data transfer
Network protocols ............................................... Ethernet 10/100, TCP/IP
Command protocol ............................................. SCPI
Dimensions
Height ................................................................. 150 mm
Width ................................................................... 245 mm
Depth .................................................................. 385 mm
Weight ................................................................. 6 kg (typical configuration)
Shipping Weight.................................................. 9.5 kg (typical configuration)
Conformity ............................................................. CE, CSA, IEC 61010 3
Equipment)
Class A: Equipment meets requirements for industrial
electromagnetic wave equipment and the seller or user should take
notice of it. This equipment is intended for use in business
environments and not to be used in homes.
clause 15.103.
reciprocal, exponential, logarithm, absolute value, average, maximum,
minimum
rd
ed.
6
Measurement Specifications
Accuracy specifications generally are valid for 6 ½ digit resolution mode (unless otherwise noted) for front panel input
(Channel 001), after a minimum of 1-hour warm-up, and within an environment temperature range of 18 °C to 28 °C.
24-hour specifications are relative to calibration standards and assume a controlled electromagnetic environment per EN
61326. The confidence level for accuracy specifications is 99 % within 1 year of calibration (unless otherwise noted).
Scan rate (typical, depending on function and range)
Fast ..................................................................... 46 channels per second max (0.02 seconds per channel)
Medium ............................................................... 10 channels per second (0.1 seconds per channel)
Slow .................................................................... 2 channels per second (0.5 seconds per channel)
Display Resolution ................................................ 4 ½ to 6 ½ digits, depending on Sample Rate or NPLC
DC Voltage
Maximum Input ...................................................... 300 V on any range
Common Mode Rejection ..................................... 140 dB at 50 Hz or 60 Hz (1 kΩ unbalance for NPLC of 1 or greater,
±500 V peak maximum in the low lead)
Normal Mode Rejection ........................................ 55 dB for NPLC of 1 or greater and power-line frequency ±0.1 %,
±20 % of range peak maximum
Measurement Method ........................................... Multi-ramp A/D
A/D Linearity .......................................................... 2 ppm of measurement + 1 ppm off range
HYDRA Series III Data Acquisition Unit
Measurement Specifications
Input Bias Current ................................................. <30 pA at 25 °C
DC Voltage Input Characteristics
Resolution
Range Resolution
100 mV 100.0000 mV
1 V 1.000000 V
10 V 10.00000 V 1 mV
100 V 100.0000 V 10 mV 1 mV
300 V 300.000 V 100 mV 10 mV 1 mV
Note:
Input beyond ±12 V is clamped. The clamp current is up to 3 mA. 10 MΩ is default input impedance.
Fast
4½ Digits
10 μV 1 μV 0.1 μV
100 μV 10 μV 1 μV
Medium
5 ½ Digits
100 μV 10 μV
6 ½ Digits
100 μV 10 MΩ ±1 %
Slow
Input Impedance
10 MΩ or >10 GΩ
10 MΩ or >10 GΩ
10 MΩ or >10 GΩ
10 MΩ ±1 %
[1]
[1]
[1]
DC Voltage Accuracy
Accuracy is given as ± (% measurement + % of range).
Range
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 %
Notes:
• For conducted disturbances on mains input >1 V from 10 MHz to 20 MHz, add 0.02 % of range. For disturbances
>3 V, accuracy is unspecified.
• For radiated disturbances >1V/m from 450 MHz to 550 MHz, add 0.02 % of range. For disturbances > 3 V/m,
accuracy is unspecified.
24 Hour
(23 ±1 °C)
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C
Outside
18 °C to 28 °C
DC Voltage Additional Errors
Digits NPLC Ch. x01 – x20
6 ½ 200
6 ½
6 ½
5 ½ 1 (Medium)
4 ½ 0.2 (Fast) 4 ½ 0.02 -
100
10 (Slow)
add 2 μV
add 2 μV
add 2 μV
add 2 μV
Additional NPLC Noise
Error
-
-
-
add 0.0008 % of range
add 0.002 % of range + 12 μV
add 0.014 % of range + 17 μV
AC Voltage
AC voltage specifications are for ac sine wave signals >5 % of range. For inputs from 1 % to 5 % of range and <50 kHz,
add an additional error of 0.1 % of range. For 50 kHz to 100 kHz, add 0.13 % of range.
Maximum Input ...................................................... 300 V rms or 425 V peak or 3 × 10
less) for any range.
Measurement Method ........................................... AC-coupled true-rms. Measures the ac component of input with up to
300 V dc bias on any range.
AC Filter Bandwidth:
Slow .................................................................... 20 Hz
Fast ..................................................................... 200 Hz
Maximum Crest Factor ......................................... 5:1 at full scale
7
volts-Hertz product (whichever is
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Calibration Manual
Additional Crest Factor Errors ............................ Crest factor 1-2, 0.05 % of full scale
Crest factor 2-3, 0.2 % of full scale
Crest factor 3-4, 0.4 % of full scale
Crest factor 4-5, 0.5 % of full scale
AC Voltage Input Characteristics
Range Resolution
100 mV 100.0000 mV
AC Voltage Accuracy
Accuracy is given as ± (% measurement + % of range).
Resolution
4 ½
Digits
10 μV 1 μV 0.1 μV
1 V 1.000000 V
10 V 10.00000 V 1 mV 100 µV
100 V 100.0000 V 10 mV 1 mV
300 V 300.000 V 100 mV 10 mV 1 mV
100 μV 10 μV 1 μV
5 ½
Digits
6 ½
Digits
10 μV
100 μV
Input Impedance
1 MΩ ±2 % shunted by 150 pF
Range Frequency
20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %
100 mV
1 V
10 V
100 V
300 V
Note:
For conducted disturbances on mains input >1 V from 10 MHz to 40 MHz, add 0.02 % of range. For disturbances >3 V,
accuracy is unspecified.
20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %
50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %
20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %
20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %
50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %
20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %
20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %
50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %
20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %
20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %
50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %
20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %
20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %
50 kHz to 100 kHz 0.55 % + 0.27 % 0.6 % + 0.27 % 0.6 % + 0.27 % 0.05 % + 0.03 %
24 Hour
(23 ±1 °C)
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C
Outside
18 °C to 28 °C
Additional Low Frequency Errors
Error is stated as % of reading.
Frequency
20 Hz to 40 Hz 0 % −
40 Hz to 100 Hz
100 Hz to 200 Hz
200 Hz to 1 kHz
>1 kHz
20 Hz 200 Hz
0 % 0.55 %
0 %
0 %
0 %
AC Filte
0.2 %
0.02 %
0 %
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HYDRA Series III Data Acquisition Unit
Measurement Specifications
DC Current
Input Protection .................................................... 0.15 A / 600 V Resettable PTC
DC Current Input Characteristics
Resolution
Range Resolution
Fast
4½
Digits
100 μA
1 mA 1.000000 mA 100 nA 10 nA 1 nA
10 mA 10.00000 mA
100 mA 100.0000 mA
100.0000 µA 10 nA 1 nA 0.1 nA
1 μA
10 μA 1 μA
Medium
5 ½
Digits
100 nA 10 nA
Slow
Digits
100 nA
6 ½
Reference
Resistance
(Ohms)
1k Ω
1k Ω
10 Ω
10 Ω
DC Current Accuracy
Accuracy is given as ± (% measurement + % of range).
Range
100 μA
1 mA 0.005 % + 0.001 % 0.015 % + 0.0011 % 0.015 % + 0.0011 % 0.002 % + 0.001 %
10 mA 0.005 % + 0.003 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %
100 mA 0.005 % + 0.001 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %
24 Hour
(23 ±1 °C)
0.005 % + 0.003 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
18 °C to 28 °C
DC Current Additional Errors
Digits NPLC
6 ½ 200 - 6 ½ 100 - 6 ½ 10 (Slow) - 5 ½ 1 (Medium) 0.0008 % of range 0.0008 % of range
4 ½ 0.2 (Fast) 0.002 % of range + 1.2 µA 0.002 % of range + 12 nA
4 ½ 0.02 0.014 % of range + 1.7 µA 0.014 % of range + 17 nA
Additional NPLC Noise Error
for 10 mA, 100 mA
Additional NPLC Noise
Error for 100 µA, 1 mA
Burden
Voltage
<1 mV
<1 mV
<1 mV
<1 mV
T.C./ °C
Outside
AC Current
Input Protection .................................................... 0.15 A / 600 V resettable PTC
Measurement Method ........................................... AC-coupled true-rms, dc-coupled to the shunt (no blocking capacitor).
AC Filter Bandwidth:
Slow .................................................................... 20 Hz
Fast ..................................................................... 200 Hz
Maximum Crest Factor ......................................... 5:1 at full scale
Additional Crest Factor Errors ............................ Crest factor 1-2, 0.05 % of full scale
Crest factor 2-3, 0.2 % of full scale
Crest factor 3-4, 0.4 % of full scale
Crest factor 4-5, 0.5 % of full scale
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Calibration Manual
AC Current Input Characteristics
Resolution
Range Resolution
100 μA
1 mA 1.000000 mA 100 nA 10 nA 1 nA
10 mA 10.00000 mA
100 mA 100.0000 mA
100.0000 µA 10 nA 1 nA 0.1 nA
4 ½
Digits
1 μA
10 μA 1 μA
5 ½
Digits
100 nA 10 nA
6 ½
Digits
100 nA
Reference
Resistance
1 kΩ
1 kΩ
10 Ω
10 Ω
Burden
Voltage
<10 mV (RMS)
<10 mV (RMS)
<20 mV (RMS)
<50 mV (RMS)
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
100 μA
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 %
20 Hz to 2 kHz
24 Hour
(23 ±1 °C)
0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C Outside
18 °C to 28 °C
Additional Low Frequency Errors
Error is stated as % of reading.
Frequency
20 Hz to 40 Hz
40 Hz to 100 Hz
100 Hz to 200 Hz
200 Hz to 1 kHz
>1 kHz
AC Filte
20 Hz 200 Hz
0 %
0 %
0 %
0 %
0 %
−
0.55 %
0.2 %
0.02 %
0 %
Frequency
Gate Times ............................................................. 100 milliseconds to 1 second.
Measurement Method ........................................... Flexible counting technique. AC-coupled input using the ac voltage
Settling Considerations........................................ When measuring frequency after a dc offset voltage change, errors
Measurement Considerations.............................. To minimize measurement errors, shield inputs from external noise
measurement function.
may occur. For the most accurate measurement, wait up to 1 second
for the input blocking capacitor to settle.
when measuring low-voltage, low-frequency signals.
Frequency Accuracy
Accuracy is given as ± % of measurement.
Range Frequency
100 mV to
[1] [2]
300 V
[1] Input >100 mV. For 10 mV to 100 mV, multiply percent measurement error by 10.
[2] Limited to 3 x 10
20 Hz to 40 Hz 0.03 % 0.03 % 0.03 % 0.001 %
40 Hz to 1 MHz
7
volt-Hertz
24 Hour
(23 ±1 °C)
0.006 % 0.01 % 0.01 % 0.001 %
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C
Outside 18
°C to 28 °C
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
Input Protection .................................................... 300 V on all ranges.
ranges.
10
HYDRA Series III Data Acquisition Unit
Measurement Specifications
Resistance Input Characteristics
Resolution
Range Resolution
100 Ω 100.0000 Ω 10 mΩ 1 mΩ 0.1 mΩ
1 kΩ 1.000000 kΩ 100 mΩ 10 mΩ 1 mΩ
10 kΩ 10.00000 kΩ 1 Ω 100 mΩ 10 mΩ
100 kΩ 100.0000 kΩ 10 Ω 1 Ω 100 mΩ
1 MΩ 1.000000 MΩ 100 Ω 10 Ω 1 Ω
10 MΩ 10.00000 MΩ 1 kΩ 100 Ω 10 Ω
100 MΩ 100.0000 MΩ 10 kΩ 1 kΩ 100 Ω
Fast
4½ Digits
Medium
5 ½ Digits
Slow
6 ½ Digits
Source Current
1 mA / 4 V
1 mA / 4 V
100 µA / 6 V
100 µA / 12 V
10 µA / 12 V
1 µA / 12 V
0.1 µA / 12 V
Resistance Accuracy
Accuracy is given as ± (% measurement + % of range). Basic accuracy specification is for 4-wire resistance. For 2-wire
resistance add 0.02 Ω internal resistance if using Channel 1 or 1.5 Ω if using channels x01 through x20, and add external
lead wire resistance.
Range
100 Ω
1 kΩ
10 kΩ
100 kΩ
1 MΩ
10 MΩ
100 MΩ
Note:
For conducted disturbances on mains input >1 V from 10 MHz to 40 MHz, add 0.6 % of range. For disturbances >3 V,
accuracy is unspecified.
24 Hour
(23 ±1 °C)
0.003 % + 0.003 % 0.008 % + 0.004 % 0.01 % + 0.004 % 0.0006 % + 0.0005 %
0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.001 % 0.0006 % + 0.0001 %
0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.001 % 0.0006 % + 0.0001 %
0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.001 % 0.0006 % + 0.0001 %
0.002 % + 0.001 % 0.008 % + 0.001 % 0.01 % + 0.001 % 0.001 % + 0.0002 %
0.015 % + 0.001 % 0.02 % + 0.001 % 0.04 % + 0.001 % 0.003 % + 0.0004 %
0.3 % + 0.01 % 0.8 % + 0.01 % 0.8 % + 0.01 % 0.05 % + 0.002 %
90 Days
(23 ±5 °C)
1 Year
(23 ±5 °C)
T.C./ °C
Outside 18 °C
to 28 °C
Resistance Additional Errors
Digits NPLC Additional NPLC Noise Error
6 ½ 200 0 % of range
6 ½ 100 0 % of range
6 ½ 10 (Slow) 0 % of range
5 ½ 1 (Medium) 0.0008 % of range
4 ½ 0.2 (Fast)(only for 2-wire)
4 ½ 0.02 (only for 2-wire)
0.002 % of range + 12 mΩ
0.01 % of range + 17 mΩ
RTD
Temperature Range .............................................. -200 °C to 1200 °C (depending on the sensor)
Resistance Range ................................................. 0 Ω to 4 kΩ
Maximum Lead Resistance (4-wire Ω) ................ 2.5 % of range per lead for 400 Ω and 4 kΩ ranges
Sample Rate
Slow .................................................................... 10 PLC
Medium ............................................................... 2 PLC
Fast ..................................................................... 1 PLC
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2638A
Calibration Manual
RTD Temperature Accuracy
Accuracy is for 4-wire 100 Ω nominal RTD, using the slow sample rate. With 3-wire PRT/RTD add 0.015 °C if using
Channel 1, or add 0.15 °C internal resistance mismatch to the accuracy specification if using channels x01 through x20,
and add external lead wire resistance mismatch. When using medium or fast sample rate (NPLC <10), add the number
given in the table to the accuracy specification. If the environment temperature is outside the specified range, multiply the
Temperature Coefficient number by the temperature deviation and add to the accuracy specification. Linear interpolation
may be used between points in the table. Specifications do not include sensor accuracy. The practical range of
temperature measurement depends on the sensor and characterization.
Temperature Accuracy
-200 °C 0.016 °C add 0.02 °C 0.0026 °C
0 °C 0.038 °C add 0.02 °C 0.0041 °C
300 °C 0.073 °C add 0.03 °C 0.0063 °C
600 °C 0.113 °C add 0.03 °C 0.0089 °C
Note:
For conducted disturbances on mains input >1 V from 10 MHz to 40 MHz, add 0.2 Celsius. For disturbances >3 V,
accuracy is unspecified.
Medium/Fast Sample
Rate (NPLC <10)
T.C./ °C Outside
18 °C to 28 °C
RTD Measurement Characteristics
Temperature Display Resolution
Range
0 Ω to 400 Ω
400 Ω to 4 kΩ
Slow
Sample Rate
0.001 °C 0.01 °C
0.001 °C 0.01 °C
Medium/Fast
Sample Rate
Source Current
1 mA
0.1 mA
Thermistor
Temperature Range .............................................. -200 °C to 400 °C (depending on the sensor)
Resistance Range ................................................. 0 Ω to 1 MΩ
Sample Rate
Slow .................................................................... 10 PLC
Medium ............................................................... 2 PLC
Fast ..................................................................... 1 PLC
12
Thermistor Temperature Accuracy
Accuracy specifications are for a 4-wire thermistor using medium or slow sample rate. With 2-wire thermistor add the
number given in the table to the accuracy specification for internal resistance. When using fast sample rate (NPLC <10),
multiply the accuracy specification by 3. If the environment temperature is outside the specified range, increase the
accuracy specification by 25 % for every 1 °C outside the specified environment temperature range. Specifications do not
include sensor accuracy. The practical range of temperature measurement depends on the sensor.
Accuracy
Temperature
-40 °C 0.002 °C 0.007 °C 0.007 °C add 0.002 °C
0 °C 0.005 °C 0.004 °C 0.003 °C add 0.004 °C
25 °C 0.013 °C 0.007 °C 0.005 °C add 0.016 °C
50 °C 0.019 °C 0.01 °C 0.011 °C add 0.05 °C
100 °C 0.116 °C 0.054 °C 0.026 °C add 0.34 °C
150 °C 0.527 °C 0.239 °C 0.1 °C add 1.7 °C
Note:
For conducted disturbances on mains input >1 V from 10 MHz to 40 MHz, add 0.2 Celsius. For disturbances >3 V,
accuracy is unspecified.
2.2 kΩ
thermistor
5 kΩ
thermistor
10 kΩ
thermistor
2-wire
HYDRA Series III Data Acquisition Unit
Measurement Specifications
Thermistor Measurement Characteristics
Temperature Display Resolution
Range
0 Ω to 98 kΩ
95 kΩ to 1 MΩ
Slow
Sample Rate
0.001 °C 0.01 °C
0.001 °C 0.01 °C
Medium/Fast
Sample Rate
Source Current
10 μA
1 μA
Thermocouple
Temperature Range .............................................. -270 °C to 2315 °C (depending on the sensor)
Voltage Range ....................................................... -15 mV to 100 mV
Sample Rate
Slow .................................................................... 10 PLC
Medium ............................................................... 2 PLC
Fast ..................................................................... 1 PLC
Thermocouple Temperature Accuracy
Accuracy specifications apply using a slow sample rate. When using a medium or fast sample rate (NPLC < 10), increase
the accuracy specification by 25 %. If the environment temperature is outside the specified range, increase the accuracy
specification by 12 % for every 1 °C outside the specified environment temperature range. Accuracy with fixed/external
CJC does not include the accuracy of the reference junction temperature. Linear interpolation may be used between
points in the table. Specifications do not include sensor accuracy. The practical range of temperature measurement
depends on the sensor.
Type
(Range)
K
-270 °C to 1372 °C
T
-270 °C to 400 °C
R
-50 °C to 1768 °C
S
-50 °C to 1768 °C
J
-210 °C to 1200 °C
N
-270 °C to 1300 °C
E
-270 °C to 1000 °C
Temperature
-200 °C
0 °C
1000 °C
-200 °C
0 °C
200 °C
400 °C
0 °C
300 °C
1200 °C
1600 °C
0 °C
300 °C
1200 °C
1600 °C
-200 °C
0 °C
1000 °C
-200 °C
0 °C
500 °C
1000 °C
-200 °C
0 °C
300 °C
700 °C
Accuracy
Fixed / External CJC Internal CJC
Channel 1 Ch. x01 – x20 Ch. x01 – x20
0.28 °C
0.10 °C
0.14 °C
0.27 °C
0.10 °C
0.08 °C
0.08 °C
0.76 °C
0.42 °C
0.33 °C
0.34 °C
0.74 °C
0.45 °C
0.37 °C
0.39 °C
0.20 °C
0.08 °C
0.11 °C
0.42 °C
0.15 °C
0.12 °C
0.14 °C
0.17 °C
0.07 °C
0.06 °C
0.08 °C
0.41 °C
0.15 °C
0.20 °C
0.40 °C
0.15 °C
0.12 °C
0.11 °C
1.13 °C
0.63 °C
0.47 °C
0.49 °C
1.11 °C
0.67 °C
0.54 °C
0.56 °C
0.29 °C
0.12 °C
0.14 °C
0.62 °C
0.23 °C
0.17 °C
0.19 °C
0.25 °C
0.10 °C
0.09 °C
0.10 °C
1.60 °C
0.62 °C
0.64 °C
1.60 °C
0.65 °C
0.47 °C
0.41 °C
1.28 °C
0.71 °C
0.52 °C
0.54 °C
1.26 °C
0.76 °C
0.60 °C
0.63 °C
1.41 °C
0.61 °C
0.53 °C
1.69 °C
0.64 °C
0.44 °C
0.45 °C
1.42 °C
0.61 °C
0.46 °C
0.45 °C
13
2638A
Calibration Manual
B
100 °C to 1820 °C
C
0 °C to 2315 °C
D
0 °C to 2315 °C
G
0 °C to 2315 °C
L
-200 °C to 900 °C
M
-50 °C to 1410 °C
U
-200 °C to 600 °C
W
0 °C to 2315 °C
300 °C
600 °C
1200 °C
1600 °C
600 °C
1200 °C
2000 °C
600 °C
1200 °C
2000 °C
600 °C
1200 °C
2000 °C
-200 °C
0 °C
800 °C
0 °C
500 °C
1000 °C
-200 °C
0 °C
400 °C
600 °C
1200 °C
2000 °C
1.32 °C
0.68 °C
0.41 °C
0.38 °C
0.23 °C
0.28 °C
0.44 °C
0.22 °C
0.26 °C
0.39 °C
0.24 °C
0.22 °C
0.33 °C
0.13 °C
0.08 °C
0.09 °C
0.11 °C
0.10 °C
0.10 °C
0.25 °C
0.10 °C
0.08 °C
0.24 °C
0.22 °C
0.33 °C
1.97 °C
1.02 °C
0.60 °C
0.55 °C
0.33 °C
0.40 °C
0.60 °C
0.32 °C
0.36 °C
0.53 °C
0.36 °C
0.32 °C
0.46 °C
0.19 °C
0.12 °C
0.12 °C
0.16 °C
0.15 °C
0.14 °C
0.37 °C
0.15 °C
0.11 °C
0.36 °C
0.32 °C
0.46 °C
1.97 °C
1.02 °C
0.60 °C
0.55 °C
0.54 °C
0.63 °C
0.91 °C
0.44 °C
0.49 °C
0.69 °C
0.36 °C
0.33 °C
0.46 °C
0.99 °C
0.62 °C
0.48 °C
0.64 °C
0.51 °C
0.41 °C
1.48 °C
0.63 °C
0.40 °C
0.36 °C
0.33 °C
0.46 °C
Thermocouple Measurement Characteristics
Temperature Display Resolution
Range
Slow
Sample Rate
-270 °C to 2315 °C 0.01 °C 0.1 °C
Digital I/O
Absolute Voltage Range ......................................... -4 V to 30 V
Input Minimum Logic High ...................................... 2.0 V
Input Maximum Logic Low ...................................... 0.7 V
Output Type ............................................................ open drain active low
Output Logic Low (<1 mA) ...................................... 0 V to 0.7 V
Maximum Sink Current ........................................... 50 mA
Output Resistance .................................................. 47 Ω
Totalizer
Absolute Voltage Range ......................................... -4 V to 30 V
Minimum Logic High ............................................... 2.0 V
Maximum Logic Low ............................................... 0.7 V
Minimum Pulse Width ............................................. 50 μs
Maximum Frequency .............................................. 10 kHz
Debounce Time ....................................................... 1.7 ms
Maximum Count ...................................................... 1048575 (20 bits)
Medium/Fast
Sample Rate
14
Trigger
Absolute Voltage Range ......................................... -4 V to 30 V
Minimum Logic High ............................................... 2.0 V
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