Fluke 3458-HFL, 8508A User Manual

Multimeter Selection Guide
Fluke 8508A & Agilent 3458/HFL

When comparing two products features and specification using sales information
it is often difficult to determine which product will meet the needs of your specific
application. This is mostly because each supplier will define specifications using
alternate methods. This Selection Guide will help you compare the specifications
and features of the Fluke 8508A Reference multimeter with the nearest
equivalent digital multimeter the Agilent 3458/HFL. Both the 8508A and the
special 3458/HFL multimeters are available through the Fluke sales channel.

The following pages summarize & segment the features of each meter into the
following three categories.

• Accuracy

• Functionality & Versatility

• Ease of Use

The 'Comments' column found in the following table provides a brief explanation
against each feature and its relevance to the intended metrology applications.

Further reference information:

1) Agilent 3458A/HFL Technical Data - 1275558 D-ENG-N

2) Fluke 8508A Extended Specifications - 1887212 D-ENG-N rev A

3) 1281Operators Handbook – 850090 issue 6

TECHNICAL INFORMATION

DC Voltage

Calibration Interval 365 day, ±1°C of last TCAL

±(ppm of setting + ppm of range), relative to calibration standards used.

Range 1281 HP3458/HFL 8508A

120.00000mV - 4 + 3 -

199.999999mV 6 + 0.5 - 2.7 + 0.5

1.20000000V - 3 + 0.3 -

1.99999999V 3 + 0.2 - 2.7 + 0.2

12.000000V - 3 + 0.05 -

19.9999999V 3 + 0.2 - 2.7 + 0.2

120.00000V - 5 + 0.3 -

199.999999V 6 + 0.1 - 4.0 + 0.2

1050.0000V 6 + 0.1 5 + 0.1 4.0 + 0.5

DC Current

Calibration Interval 365 day, ±1°C of last TCAL

±(ppm of setting + ppm of range), relative to calibration standards used.

Range 1281 HP3458/HFL 8508A

120.000nA - 30 + 400 -

1.200000µA - 20 + 40 -

12.000000µA - 20 + 10 -

120.00000µA - 20 + 8 -

199.99999µA 25 + 2 - 6.5 + 2.0

1.2000000mA - 20 + 5 -

1.9999999mA 25 + 2 - 6.5 + 2.0

12.000000mA - 20 + 5 -

19.999999mA 25 + 2 - 8.0 + 2.0

120.00000mA - 35 + 5 -

199.99999mA 50 + 5 - 33 + 4.0

1.0500000A - 110 + 10 -

1.9999999A 150 + 10 - 170 + 8.0

19.999999A - - 380 + 20

Resistance

Calibration Interval 365 day, ±1°C of last TCAL

±(ppm of setting + ppm of range), relative to calibration standards used.

Range 1281 HP3458/HFL 8508A

1.99999999 Ohm - - 10 + 2.0

12.00000 Ohm - 10 + 5 -

19.9999999 Ohm 12 + 1.0 - 7.0 + 0.7

120.00000 Ohm - 8 + 5 -

199.999999 Ohm 8 + 0.3 7.0 + 0.25

1.2000000 kOhm - 7.5 + 0.5 -

1.99999999 kOhm 6 + 0.3 - 7.0 + 0.25

12.000000 kOhm - 7.5 + 0.5 -

19.9999999 kOhm 6 + 0.3 - 7.0 + 0.25

120.00000 kOhm - 7.5 + 0.5 -

199.999999 kOhm 6 + 0.3 - 7.0 + 0.25

1.2000000 MOhm - 15 + 2 -

1.99999999 MOhm 10 + 0.7 - 7.0 + 0.5

12.000000 MOhm - 50 + 10 -

19.9999999 MOhm 20 + 4.0 - 9.0 + 5.0

120.00000 MOhm - 500 + 10 -

199.999999 MOhm 200 + 45 - 30 + 50

1.2000000 GOhm - 5000 + 10 -

1.99999999 GOhm 2000 + 450 - 500 + 500

AC Current ±(ppm of setting + ppm of range), relative to calibration standards used.

Calibration Interval 365 day, ±1°C of last TCAL

Range Frequency 1281 HP3458/HFL 8508A

120.0000µA 10Hz - 20Hz - 4000 + 200 -

199.9999µA 1Hz - 10Hz - - 250 + 100

1.2000000mA 10Hz - 20Hz - 4000 + 200 -

1.999999mA 1Hz - 10Hz - - 250 + 100

12.00000mA 10Hz - 20Hz - 4000 + 200 -

19.99999mA 1Hz - 10Hz - - 250 + 100

120.0000mA 10Hz - 20Hz - 4000 + 200 -

199.9999mA 1Hz - 10Hz - - 250 + 100

1.050000A 10Hz - 20Hz - 4000 + 200 -

1.999999A 10Hz - 1kHz 500 + 200 - -

19.99999A 10Hz - 2kHz - - 800 + 100

20Hz - 45Hz - 1500 + 200 ­45Hz - 100Hz - 600 + 200 ­100Hz - 5kHz - 600 + 200 -

10Hz - 5kHz 200 + 200 - ­10Hz - 10kHz - - 250 + 100
10kHz - 30kHz - - 600 + 100
30kHz - 100kHz - - 4000 + 100

20Hz - 45Hz - 1500 + 200 ­45Hz - 100Hz - 600 + 200 ­100Hz - 5kHz - 300 + 200 ­5kHz - 20kHz - 600 + 200 ­20kHz - 50kHz - 4000 + 400 ­50kHz - 100kHz - 5500 + 1500 -

10Hz - 5kHz 200 + 100 - ­10Hz - 10kHz - - 250 + 100
10kHz - 30kHz - - 600 + 100
30kHz - 100kHz - - 4000 + 100

20Hz - 45Hz - 1500 + 200 ­45Hz - 100Hz - 600 + 200 ­100Hz - 5kHz - 300 + 200 ­5kHz - 20kHz - 600 + 200 ­20kHz - 50kHz - 4000 + 400 ­50kHz - 100kHz - 5500 + 1500 -

10Hz - 5kHz 200 + 100 - ­10Hz - 10kHz - - 250 + 100
10kHz - 30kHz - - 600 + 100
30kHz - 100kHz - - 4000 + 100

20Hz - 45Hz - 1500 + 200 ­45Hz - 100Hz - 600 + 200 ­100Hz - 5kHz - 300 + 200 ­5kHz - 20kHz - 600 + 200 ­20kHz - 50kHz - 4000 + 400 ­50kHz - 100kHz - 5500 + 1500 -

10Hz - 5kHz 200 + 100 - ­10Hz - 10kHz - - 250 + 100
10kHz - 30kHz - - 600 + 100

20Hz - 45Hz - 1600 + 200 ­45Hz - 100Hz - 800 + 200 ­100Hz - 5kHz - 1000 + 200 ­5kHz - 20kHz - 3000 + 200 ­20kHz - 50kHz - 10000 + 400 -

10Hz - 2kHz - - 600 + 100
1kHz - 5kHz 1500 + 400 - ­2kHz - 10kHz - - 700 + 100
10kHz - 30kHz - - 3000 + 100

2kHz - 10kHz - - 2500 + 100

AC Voltage ±(ppm of setting + ppm of range), relative to calibration standards used.

Calibration Interval 365 day, ±1°C of last TCAL

Range Frequency 1281 HP3458/HFL 8508A

12.00000mV 1Hz - 40Hz - 300 + 300 ­40Hz - 1kHz - 200 + 110 ­1kHz - 20kHz - 300 + 110 ­20kHz - 50kHz - 1000 + 110 ­50kHz - 100kHz - 5000 + 110 ­100kHz - 300kHz - 40000 + 200 -

120.0000mV 1Hz - 40Hz - 70 + 40 ­40Hz - 1kHz - 70 + 20 ­1kHz - 20kHz - 140 + 20 ­20kHz - 50kHz - 300 + 20 ­50kHz - 100kHz - 800 + 20 ­100kHz - 300kHz - 3000 + 100 ­300kHz - 1MHz - 10000 + 100 ­1MHz - 2MHz - 15000 + 100 -

199.9999mV 1Hz - 10Hz - - 120 + 70
10Hz - 40Hz - - 120 + 70
40Hz - 100Hz 100 + 20 - 100 + 20
100Hz - 2kHz 100 + 20 - 100 + 10
2kHz - 10kHz 100 + 20 - 100 + 20
10kHz - 30kHz 300 + 40 - 300 + 40
30kHz - 100kHz 700 + 100 - 700 + 100

1.2000000V 1Hz - 40Hz - 70 + 40 ­40Hz - 1kHz - 70 + 20 ­1kHz - 20kHz - 140 + 20 ­20kHz - 50kHz - 300 + 20 ­50kHz - 100kHz - 800 + 20 ­100kHz - 300kHz - 3000 + 100 ­300kHz - 1MHz - 10000 + 100 ­1MHz - 2MHz - 15000 + 100 -

1.999999V 1Hz - 10Hz - - 100 + 60
10Hz - 40Hz - - 100 + 10
40Hz - 100Hz 80 + 10 - 80 + 10
100Hz - 2kHz 60 + 10 - 60 + 10
2kHz - 10kHz 80 + 10 - 80 + 10
10kHz - 30kHz 200 + 20 - 200 + 20
30kHz - 100kHz 500 + 100 - 500 + 100
100kHz - 300kHz 3000 + 1000 - 3000 + 1000
300kHz - 1MHz 10000 + 10000 - 10000 + 10000

12.00000V 1Hz - 40Hz - 70 + 40 ­40Hz - 1kHz - 70 + 20 ­1kHz - 20kHz - 140 + 20 ­20kHz - 50kHz - 300 + 20 ­50kHz - 100kHz - 800 + 20 ­100kHz - 300kHz - 3000 + 100 ­300kHz - 1MHz - 10000 + 100 ­1MHz - 2MHz - 15000 + 100 -

AC Voltage ±(ppm of setting + ppm of range), relative to calibration standards used.

Calibration Interval 365 day, ±1°C of last TCAL

Range Frequency 1281 HP3458/HFL 8508A

19.99999V 1Hz - 10Hz - - 100 + 60

10Hz - 40Hz - - 100 + 10
40Hz - 100Hz 80 + 10 - 80 + 10
100Hz - 2kHz 60 + 10 - 60 + 10
2kHz - 10kHz 80 + 10 - 80 + 10
10kHz - 30kHz 200 + 20 - 200 + 20
30kHz - 100kHz 500 + 100 - 500 + 100
100kHz - 300kHz 3000 + 1000 - 3000 + 1000
300kHz - 1MHz 10000 + 10000 - 10000 + 10000

120.0000V 1Hz - 40Hz - 200 + 40 -

40Hz - 1kHz - 200 + 20 ­1kHz - 20kHz - 200 + 20 ­20kHz - 50kHz - 350 + 20 ­50kHz - 100kHz - 1200 + 20 ­100kHz - 300kHz - 4000 + 100 ­300kHz - 1MHz - 15000 + 100 -

199.9999V 1Hz - 10Hz - - 100 + 60

10Hz - 40Hz - - 100 + 10
40Hz - 100Hz 80 + 10 - 80 + 10
100Hz - 2kHz 60 + 10 - 60 + 10
2kHz - 10kHz 80 + 10 - 80 + 10
10kHz - 30kHz 200 + 20 - 200 + 20
30kHz - 100kHz 500 + 100 - 500 + 100
100kHz - 300kHz 3000 + 1000 - 3000 + 1000
300kHz - 1MHz 10000 + 10000 - 10000 + 10000

1050.000V 1Hz - 10Hz - 400 + 40 100 + 70

10Hz - 40Hz - 400 + 40 100 + 20
40Hz - 1kHz - 400 + 20 ­40Hz - 10kHz 80 + 10 - 80 + 20
1kHz - 20kHz - 600 + 20 ­10kHz - 30kHz 200 + 20 - 200 + 40
20kHz - 50kHz - 1200 + 20 ­30kHz - 100kHz 500 + 100 - 500 + 200
50kHz - 100kHz - 3000 + 20 -

Fluke 8508A 3458/HFL

8508A vs 3458/HFL

Functional & Versatility

Comments

Parameters

Full Scale (dc & ac Voltage) 200mV, 2V, 20V, 200V, 1050Vrms

Full Scale (dc & ac current)

AC Measurement
(Bandwidth)

Full Scale (Resistance)

200 Ohm Resistance Range.

200uA, 2mA, 20mA, 200mA, 2A &
20A

AC Voltage - 1MHz (2%)
AC Current - 100kHz (0.4%)

2Ω, 20Ω, 200Ω, 2kΩ, 20kΩ,
200kΩ, 2MΩ, 20MΩ, 200M
2GΩ, 20GΩ (eleven ranges)

Selectable excitation current ­10mA & 1mA

Ω,

120mV, 1.2V, 12V, 120V,
1050Vdc (ac = 700Vrms)

100nA, 1uA, 120uA, 1.2mA,
12mA, 120mA, 1.05A

AC Voltage - 1MHz (1%)
AC Voltage - 10MHz (15%)
AC Current - 100kHz (0.7%
Typical)

12Ω, 120Ω, 1.2kΩ, 12kΩ,
120kΩ, 1.2MΩ, 12MΩ,
120MΩ, 1.2GΩ (nine ranges)

Fixed excitation current ­10mA

8508A maintains >10Gohm input impedance
to 20Vdc. This compares with 12V on
3458/HFL. The 8508A 1050Vrms
measurement is often used to calibrate
calibrators at 1000 Vrms output.
3458A/HFL has lower current ranges with a
sensitivity of 1pA compared with 10pA on
the 8508A – the 3458/HFL datasheet does
state that lower ranges have ‘typical’
uncertainty only. 8508A states typical above
10kHz and 2GOhm for resistance.

A 20Amp range on the 8508A improves
calibration of Multi-product calibrators. This
reduces the need for additional external
shunts.
A DMM with 10 MOhm input impedance is
generally not useful for precision ac
measurement above 1MHz. A 50 Ohm
termination at these frequencies is more
desirable.
The 8508A high frequency Current
uncertainty will help maintain good TURs
when calibrating Multi-Product calibrators.

8508A has a wide resistance measurement
range. 8508A measurement resolution of

10n

Ω this compares with 10uΩ on

3458/HFL
Errors due to self-heating within the resistor

under test are minimized when the
multimeter low excitation current is
maintained. Use in conjunction with RTD or
low resistance measurements.

8508A vs 3458/HFL

Functional & Versatility

Parameters

Comments

High Resistance
Measurement (compliance
voltage)

Tru-Ohms or Offset
Compensated Resistance
technique.

Store RTD temperature
coefficients

ACAL Not Required

Auto-zero (A-zero) Range zero is enabled by operator

Low impedance low Current
measurement technology

ACV measurement
technique

Test Voltage or Full Scale
stimulus = 200V

Current Reversal Switched Current

Supports a wide variety of PRT &
SPRT sensors

Yes No

Analog True rms

Test Voltage or Full Scale
stimulus @ 1.2GΩ = 5V

Not Available

Required every 24hrs or

of last ACAL

A-zero should be enabled to
maintain specification

Analog, Synchronous and
Random sampled ac

±1º C

Reduces errors when performing high
resistance measurement (feature available
8508A - 20MΩ to 20GΩ range only)

Current reversal reduces errors caused by
thermal emfs as does switched current but
reversal technique has the added benefit of
reducing errors due to self heating

PRT calibration coefficients are stored (max
100 probes) within the 8508As internal
memory.
8508A - Precision without the need for
internal drift corrections. ACAL will overwrite
last stored value and cannot be retrieved.
This might be important for users that
require ‘as found data’.
Auto-zero must be enabled on 3458A/HFL if

environment exceeds
zero. Zero/nulling meters before
measurement is accepted metrology
practice.
8508A is less intrusive when compared with
conventional meters when measuring low
magnitude current sources. The 8508A
input impedance on the 200uA range is 60
Ohm. This low impedance mimics
technology normally found in Electrometers
and picoampmeters. This compares with 5k
– 10k Ohm on other DMMs.
Digitize sub sampled techniques are useful
when measuring low frequency <1Hz input
signals.

±1°C of last Input

ACV & DCV 4 wire input.

Remote switched GUARD
Terminal

Read rate

Calibration technique

Selectable 2 and 4-wire
measurement.

IEEE controlled Manual Switch

High Speed - 150 readings/sec @

5.5 digit resolution

Individual Function and Range
calibration.

Unavailable

High Speed - 100,000
reading/sec @ 4.5 digit
resolution

Artifact Calibration & Individual
Function and Range
calibration.

4-wire sense measurement support
improved accuracy when calibrating
calibrators with 4 wire sense output.

IEEE control of GUARD terminal helps fully
automate calibration without need for
manual switching.

High read rates are useful for some ATE
applications where accuracy is not of high
priority.

Both techniques have their merits. 8508A
and associated calibration technique
provides full results traceability. ‘As found’
data is difficult to determine using 3458/HFL
‘artifact’ calibration.
Artifact calibration provides a low cost
solution for adjustment.

8508A vs 3458/HFL

Ease of Use Parameters

Rear input switched remotely
using IEEE 488 commands
Instrument simultaneously
displays Frequency as well as
the AC voltage & current.

Two channel Ratio reference
measurement

Able to load SPRT/PRT
calibration linearization
coefficients and display
temperature and resistance
simultaneously.

Constant energization current on
Resistance Ratio function.

GPIB Remote interface IEEE-488.2 IEEE-488.1

Self-cal or ACAL function Not Required Required to meet specification

Yes (8508A/01 only)

Yes (up to100) No

Comments

Yes No

Yes Selectable

Yes, but limited to 12Vdc on

the Reference input

Yes

No (the 3458/HFL does not

measure resistance ratio)

The 3458/HFL must be switched manually
using a front panel button.

Requires further commands or key presses
to determine frequency.

8508A can accept and compare dc to dc, ac
to ac, dc to ac, Resistance to Resistance &
Temperature to Temperature. Auto-ranging
allows inputs of different magnitude to be
connected and compared. Feature supports
the replacement of Kelvin Varley dividers,
resistance bridge and ac/dc transfer
standards

8508As displays resistance and temperature
simultaneously.

When measuring Resistance in Ratio mode
not only is the current the same but it is
reversed to help reduce thermal offsets.

8508A components are selected for
minimum drift over time and temperature.
Therefore does not require frequent internal
calibration when conditions exceed TCAL
specification.

8508A Options and Accessories:

Model Description
8508A

8508A/01

Accessories

8508A-SPRT

8508A-PRT

8508A-LEAD

Y8508

Y8508S

8508A-7000K

1883673

1256990

Model Description
3458/HFL/E
3458/HFLM/E
3458/HFL/E/AC
3458/HFLM/E/120/AC

8.5 digit Reference Multimeter

8.5 digit Reference Multimeter with Rear Input Ratio measurement

Standard Platinum Resistance Thermometer

Platinum Resistance Thermometer

Comprehensive Measurement Lead Kit

Rack Mount Kit

Rack Mount Kit Slides

Calibration kit comprising 1GOhm Standard and connecting leads.

UKAS Accredited Certification

NVLAP Accredited Certification

Special Lab DMM, English
Special Lab DMM, English, with -001 Extended Memory Option
Special Lab DMM, English, + Accredited Calibration
Special Lab DMM, English, with -001 Extended Memory Option + Accredited Calibration

Notes: