Hioki 3257-50 User manual

3257-51
DIGITAL HiTESTER
3257-50
Instruction Manual
June 2012 Revised edition 9 3257C981-09 12-06H

i
Introduction ............................................................. 1
Inspection ............................................................... 1
Safety Notes ........................................................... 2
Usage Notes........................................................... 6
Chapter 1 Overview 10
1.1 Product Overview ................................. 10
1.2 Features ................................................ 10
1.3 Parts Names and Functions .................11
Chapter 2 Measurement Procedures 19
2.1 Pre-Operation Inspection...................... 20
2.2 Voltage Measurement........................... 22
2.3 Frequency Measurement...................... 24
2.4 Current Measurement........................... 25
2.5 Resistance Measurement..................... 28
2.6 Continuity Check................................... 29
2.7 Diode Check......................................... 30
2.8 Duty Factor Measurement.................... 31
Chapter 3 Additional Functions 33
3.1 HOLD AUTO Function .......................... 33
3.2 HOLD Function ..................................... 34
3.3 Overflow Warning Function .................. 35
3.4 Relative Display Function .....................36
3.5 Auto Power Save Function ................... 38
3.6 Dynamic Recording Function ................ 39
3.7 Memory Function .................................. 40
Contents

ii
Chapter 4 Specifications 43
4.1 General Specifications ..........................43
4.2 Accuracy ................................................46
4.3 L9207-10 TEST LEAD Specifications ...49
Chapter 5 Maintenace and Service 50
5.1 Replacing the Batteries and Fuses ....... 50
5.2 Cleaning ................................................52
5.3 Service ..................................................52
5.4 Error Message .......................................52

1
Thank you for purchasing the HIOKI "3257-50/51
DIGITAL HiTESTER". To obtain maximum perfor-
mance from the product, please read this manual
first, and keep it handy for future reference.
• When you receive the product, inspect it carefully
to ensure that no damage occurred during ship-
ping. In particular, check the accessories, panel
switches, and connectors. If damage is evident, or
if it fails to operate according to the specifications,
contact your dealer or Hioki representative.
• Before using the product the first time, verify that it
operates normally to ensure that the no damage
occurred during storage or shipping. If you find any
damage, contact your dealer or Hioki representa-
tive.
• Before using the instrument, check that the coating
of the test leads is not damaged and that no white
or red portions (insulation layers) are showing from
the inside and that no metal parts are exposed.
Using the product under such conditions could
result in electrocution. Replace the test leads and
probes with the specified Hioki Model L9207-10.
Introduction
Inspection

2
•L9207-10 TEST LEAD .............. 1
•Instruction Manual..................... 1
•R03 Manganese battery............ 2
(Supplied with this product,
for monitor)
•9378 CARRYING CASE*1
( 3257-50 only)
•Protective holster*2( 3257-51 only)
This manual contains information and warnings
essential for safe operation of the product and for
maintaining it in safe operating condition. Before
using the product, be sure to carefully read the fol-
lowing safety notes.
3257-50
*1
3257-51
*2
Accessories
Safety Notes
This product is designed to conform to IEC
61010 Safety Standards, and has been thor-
oughly tested for safety prior to shipment.
However, mishandling during use could
result in injury or death, as well as damage to
the product. Be certain that you understand
the instructions and precautions in the man-
ual before use. We disclaim any responsibil-
ity for accidents or injuries not resulting
directly from product defects.

3
Safety Symbols
In the manual, the symbol indicates particu-
larly important information that the user should
read before using the product.
The symbol printed on the product indicates
that the user should refer to a corresponding topic
inthemanual(markedwiththe symbol) before
using the relevant function.
Indicates that dangerous voltage may be present
at this terminal.
Indicates a double-insulated device.
Indicates a grounding terminal.
Indicates DC (Direct Current).
Indicates AC (Alternating Current).
Indicates DC (Direct Current) or AC (Alternating
Current).

4
The following symbols in this manual indicate the
relative importance of cautions and warnings.
Other Symbols
Accuracy We define measurement tolerances in terms of f.s.
(full scale), rdg. (reading) and dgt. (digit) values,
with the following meanings:
Indicates that incorrect operation presents an ex-
treme hazard that could result in serious injury or
death to the user.
Indicates that incorrect operation presents a sig-
nificanthazard thatcould result inserious injuryor
death to the user.
Indicates that incorrect operation presents a pos-
sibility of injury to the user or damage to the prod-
uct.
Advisory items related to performance or correct
operation of the product.
Indicates the quick guide for operations
Indicates the prohibited action
f.s. (maximum display value or scale length)
The maximum displayable value or the full length
of the scale. This is usually the maximum value of
the currently selected range.
rdg. (reading or displayed value)
Thevaluecurrentlybeing measured andindicated
on the measuring product.
dgt. (resolution)
The smallest displayable unit on a digital measur-
ing product, i.e., the input value that causes the
digital display to show a "1".

5
Measurement categories
This product complies with CATIII (1000 V), CATIV (600 V)
safety requirements.
To ensure safe operation of measurement products, IEC 61010
establishes safety standards for various electrical environments,
categorized as CAT II to CAT IV, and called measurement cate-
gories.
Using a measurement product in an environment designated
with a higher-numbered category than that for which the product
is rated could result in a severe accident, and must be carefully
avoided.
Use of a measurement instrument that is not CAT-rated in CAT II
to CAT IV measurement applications could result in a severe
accident, and must be carefully avoided.
CAT II Primary electrical circuits in equipment connected to
an AC electrical outlet by a power cord (portable tools,
household appliances, etc.) CAT II covers directly
measuring electrical outlet receptacles.
CAT III Primary electrical circuits of heavy equipment (fixed installations) connected directly to the distribution pan-
el, and feeders from the distribution panel to outlets.
CAT IV The circuit from the service drop to the service en- trance, and to the power meter and primary overcur-
rent protection device (distribution panel).

6
Follow these precautions to ensure safe operation
and to obtain the full benefits of the various func-
tions.
Usage Notes
• To avoid electric shock, do not allow the
product to get wet, and do not use it when
your hands are wet.
• Do not use the product where it may be
exposed to corrosive or combustible
gases. The product may be damaged or
cause an explosion.

7
Observe the following to avoid damage to the
product.
• Installation and Operating Environment
Between 0°C and 40°C; 80% RH or less;
indoors only. However, it can be safely operated
at as low as -10°C.
• Do not store or use the product where it could
be exposed to direct sunlight, high temperature
or humidity, or condensation. Under such condi-
tions, the product may be damaged and insula-
tion may deteriorate so that it no longer meets
specifications.
• This product is not designed to be entirely
water- or dust-proof. To avoid damage, do not
use it in a wet or dusty environment.
• Do not use the product near a device that gener-
ates a strong electromagnetic field or electro-
static charge, as these may cause erroneous
measurements.
• To avoid damage to the product, protect it from
vibration or shock during transport and handling,
and be especially careful to avoid dropping.
• Adjustments and repairs should be made only
by technically qualified personnel.
• If the protective functions of the product are
damaged, either remove it from service or mark
it clearly so that others do not use it inadvert-
ently.
• To avoid corrosion from battery leakage, remove
the batteries from the product if it is to be stored
for a long time.
Direct
sunlight
High temper-
ature, high
humidity,dust
Electromag-
netic radiation
Impact,
dropping

8
• Accurate measurement may be impossible in the
presence of strong magnetic fields, such as near
transformers and high-current conductors, or in
the presence of strong electromagnetic fields
such as near radio transmitters.
• To avoid battery depletion, turn the function
selector OFF after use (the Auto Power Save
feature consumes a small amount of current).
• The indicator appears when battery voltage
becomes low. Replace the batteries as soon as
possible.
• Rectification method (true RMS and mean)
There are two methods for converting AC signal
to an RMS value: the true RMS method (true
RMS indication) and the mean method (mean
rectification RMS indication). Although the two
methods both yield the same value for a perfect
(undistorted) sine wave, differences occur when
the target waveform becomes distorted. The
instrument uses the mean method (rectification
RMS indication method). Input waveforms are
treated as sine waves (single-frequency only),
and the AC signal's mean value is calculated
and converted to an RMS value. Waveform dis-
tortion causes the measurement error to
increase. Waveforms containing harmonic com-
ponents are calculated using the RMS formula
and displayed.

9
Handling the Cables
• Removable sleeves are attached to the
metal pins at the ends of the test leads.
To prevent a short circuit accident, be sure
to use the test leads with the sleeves
attached when performing measurements
in the CAT III and CAT IV measurement
categories . Remove the sleeves from the
test leads when performing measurements
in the and CAT II measurement categories.
For details on measurement categories,
see "Measurement categories" (page 5) in
the instruction manual.
• To prevent an electric shock accident, con-
firm that the white or red portion (insulation
layer) inside the cable is not exposed. If a
color inside the cable is exposed, do not
use the cable.
• The ends of the test leads are sharp. Be careful
to avoid injury.
• To avoid damaging the cables, do not bend or
pull the cables.
• Avoid stepping on or pinching the cable, which
could damage the cable insulation.

1.1 Product Overview
10
This measurement product is a multi-functional
digital multimeter capable of measuring DC and
AC voltages, DC and AC currents, the resistance,
and the duty factor, and checking the diode and
continuity.
Since a true RMS measurement system is used,
the measurement product can accurately measure
even distorted waveforms.
Compliance with CE marking requirements
The measurement product is designed to comply
with the international safety standard (IEC61010-
1) and EMC standards.
Safety-designed handy digital multimeter
The measurement product is equipped with test-
lead misinsertion preventive shutters and fast-act-
ing fuses at the current measurement terminals.
Multi-functional and duty-factor measurement
• The duty factor, which is used to analyze pulse
control signals, can also be measured.
• The Hold Auto function allows measured values to
be maintained by simply disconnecting the test
leads.
• The Hold function maintains the displayed value.
• The Memory function saves the held value dis-
played.
• The Recording function displays the maximum,
minimum, average, and currently measured values
selectively.
• The Relative function displays any discrepancy
from the reference.
Overview Chapter 1
1.1 Product Overview
1.2 Features

11
1.3 Parts Names and Functions
1.3 Parts Names and Functions
*: for details, see
the following
pages
Aterminal
Terminal used to
measure cur-
rents in 10-A
mode
LCD display *
H.AUTO/REL
Button *
RANGE
Button *
Function
Selector
(Selectsfunctions
and turns the
power on/off)
A.mA terminal
Terminal used to
measure currents in
A/mA mode
V.terminal
Terminalusedto
measure voltag-
es and resis-
tances
(red test lead)
COM terminal
Terminal common to
all functions
(black test lead)
REC•MEMO
Button
(Pressthisbutton
to change to the
function indicat-
ed in blue.)
For other func-
tions, see the fol-
lowing pages.
The terminal shutter works together with the
function selector to prevent incorrect operation.
Operating the function switch while the test
leads are connected may damage the instru-
ment.

1.3 Parts Names and Functions
12
Indicates Recording function
Indicates Continuity Check function
Indicates Diode Check function
Indicates Auto Power
Save is enabled
Frequency units
Resistance and
continuity check
units
Voltage and di-
ode check units
Current units
Indicates the
memory data
number
Bar-graph scale (42 dots)
Bar graph (with polarity indicator)
LCD(Display)
Indicates HOLD AUTO/
HOLD function
Indicates Relative function
Indicates Duty Factor
function
Indicates Auto-
ranging
function
Indicates DC
voltage/cur-
rent function
Indicates AC
voltage/cur-
rent function
Indicates low battery voltage
Lights up when the voltage
drops below the battery
accuracy guarantee voltage
(2.350.15 V) Decimal point
• Changes to the
function indicated in
blue
• Toggles between
AC and DC
modes(Current
measurement)
(page 25)
• Recording function
(Displays MAX/MIN/
AVG)
*1 (page 39)
• Duty Factor mea-
surement (page 31)
• Memory Function
(page 40)
• Cancels the Auto
Power Save func-
tion *2 (page 38)
• Changes the manu-
al range and selects
range
• Changes the auto
range from the man-
ual range*1
• Changes the input
level (Frequency
function) (page 24)
• Calls data from
memory*2 (page 41)
• HOLD AUTO func-
tion (Holds the mea-
sured value) (page
33)
• Turns the HOLD
function on/off *2
(page 34)
• Turns the Relative
function (displaying
the relative value)
on/off *1 (page 36)
REC•MEMO H.AUTO/REL RANGE
*1:Press thebutton forat least 1 second(REC
and REL require the button to be pressed
for a longer time).
*2: Turn on the power while pressing the but-
ton, and hold the button down until a beep-
ing sound is generated (power-on option).

13
1.3 Parts Names and Functions
Measurements Operations (page)
AC voltage 22
DC voltage 22
DC/AC Current
(40 A) 26
DC/AC Current
(400/4000 A) 26
DC/AC Current
(40/400 mA) 27
DC/AC Current
(10A) 27
Resistance 28
Continuity 29
Diode 30
(Diode Check function)
Continuity function
Resistance function
DC voltage function
(Duty Factor function)
(Frequency
function)
AC voltage
function
Power OFF
40A DC/AC current
function
A DC/AC current
function
mA DC/ACcurrent
function
10A DC/AC
current function
Function Selector Press
REC•MEMO when the
function in parentheses is being
used.
Quick Reference
Indicates the function selector position
Indicates the terminal to which the red
test lead should be connected
Indicates the terminal to which the
black test lead should be connected
Switches between
measurement to
display in paren-
theses.
V
REC•MEMO
( )
Example
V
Measurement
V
Measurement
40  A
( )
REC • MEMO
Measurement
 A
( )
REC • MEMO
Measurement
mA
( )
REC • MEMO
Measurement
10A
( )
REC • MEMO
Measurement

Measurement
( )
REC • MEMO
Measurement
( )
REC • MEMO
Measurement

1.3 Parts Names and Functions
14
Frequency 24
Duty factor 31
V
REC • MEMO RANGE
( 1 - 4 )
"Hz" lights up
Measure-
ment
V
REC • MEMO  2
RANGE
( 1 - 4 )
( )
Measure-
ment
Hold the measured value. (HOLD AUTO function)
Thisfunctionis used whenthe displayedvalue cannotbe checkedduring
measurement (such as when necessary to measure the conductor in a
dark place or using both hands.
33
Hold the measured value. (HOLD function)
34
"O.F" is displayed to provide a warning
(Overflow Warning function)
When the measured value exceeds the maxi-
mum value, "O.F" is displayed. 35
Use this function to check any discrepancy from the reference,
or to control the resistance for the purpose of zero adjustment
(Relative function)
Cancellation: H.AUTO / REL (press again)
36
Quick Reference (application)
: Turn on the power while pressing
the button (hold the button down
until a beeping sound is generated).
:Button
REC•MEMO
REC•MEMO
<1 second:
Press the button for at least 1 second.
Example
V/ V//
40A/A/mA/
10A
H.AUTO/REL
"HOLD"
Blinking (Intermittent
sound)
Movethetestleadsawayfrom
the measurement object.
V/ V/Hz/
////
40A/A/mA/
10A
H.AUTO/REL H.AUTO/REL
Measure-
ment
V/ V/40A/
A/mA/10A
V/ V//
40A/A/mA/
10A
H.AUTO/REL
Displaythe
reference. (<1 second) ("REL"
lights up)

15
1.3 Parts Names and Functions
Cancel the Auto-Power Save function.
(Auto-Power Save function)
Enable the Power Save function: 38
Check the maximum, minimum, and average values during
measurement. (Recording function)
MAX:maximum value/ MIN:minimum value/
AVG:average value/ MAX MIN AVG:
Current value
Cancellation: REC•MEMO (press again)
39
Save the measured value to memory. (Memory function)
40
Call the saved data.
41
Delete all data from memory.
41
V/ V/Hz/
////
40A/A/mA/
10A
REC•MEMO
Press this button until a
beeping sound is generated.
OFF
Function
change ("APS"
lights up) Power
Save
mode
After
10 minutes
V/ V//
40A/A/mA/
10A
REC•MEMO
(<1 second)
H.AUTO/REL
( MAX MIN AVG )
(" MAX MIN AVG"
lights up
)
V/ V//
40A/A/mA/
10A
Hold the dis-
played value ("MEM."
lights up)
REC•MEMO
H.AUTO/REL
V/ V//
40A/A/mA/
10A
Memory-data
display
Select MEM#.
RANGE RANGE
V
V/ V//
40A/A/mA/
10A
RANGE
REC•MEMO
RANGE
(<1 second)
V

1.3 Parts Names and Functions
16
Pin
(Probe tip)
(Metal pin)
Connect to the object being tested.
Length 4 mm or less (sleeve attached)
19 mm or less (sleeve removed)
Diameter approx. 2 mm
Sleeve Attach to the pins to prevent short circuit accidents.
Barrier Represents the safe handling distance from the
pins.
Cable Double sheathed cables.
Length Approx. 900 mm
Diameter approx. 3.6 mm
Plug Connect to the test terminals on this instrument.
Black
Red
Plug Cable Pin
Barrier Sleeve
L9207-10 TEST LEAD