Hioki 8870-20 User manual

MEMORY HiCORDER
Measurement Guide
8870-20
October 2013 Revised edition 4 8870B980-04 13-10H

Introduction
1
Thank you for purchasing the HIOKI "Model 8870-20 Memory HiCorder."
This Measurement Guide consists of some basic application examples. Before using
the instrument, be sure to read the Instruction Manual carefully.
Introduction
Operation and Screen
Types (p. 2) Describes the screen types and an overview of the
operating keys
Measurement Procedure
(p. 4) Describes procedures from measurement prepara-
tion to analysis
Commercial Power Mains
Measurement (p. 6)
Shows the method for recording 220 V commercial
mains waveforms, and describes how to save data
after measurement.
To Monitor for Abnormal
Phenomena (p. 8)
Describes how to record abnormal phenomena such
as voltage drop like those that occur during electrical
outages as an example type of phenomena.
Also describes continuous monitoring using the trig-
ger function to record only particular phenomena,
and automatic saving while measuring.
To Measure Current (p. 10) Describes how to record current waveforms using a
clamp-on probe, and how to use the scaling function
to display current values.
Analysis (p. 12) View and calculate waveform measurement values
using the A/B cursors.

Operation and Screen Types
2
Operation and Screen Types
Select the item to
change.
Show available
setting options.
Select the desired
setting.
Changing screen contents
CF Card Slot
Logic Connector
External control terminals
AC Adapter
Socket CHARGE LED
USB Port
POWER
Switch
Operating Keys
(Rear)
Battery
Compartment
Apply the new set-
ting,
or cancel it.
BNC Terminals
WAVE/DATA
Selects among waveform
screen displays (p. 3).
SET
Displays the Settings
screens, and switches
among the screen tabs with
each press (p. 3).
FILE
Displays file information
(p. 3).
GAUGE
Alternately displays and
hides the measurement
scale on the Waveform
screen.
(Manual trigger)
Press to trigger manually.
ESC
Cancels changes to set-
tings.
Cursor Keys
Moves the position
of the cursor (blink-
ing selection) on
the screen.
ENTER
Accepts displayed
settings.
KEY LOCK
Disables keypad
operations. Press
and hold the left
and right cursor keys simul-
taneouslyforthreeseconds
to lock and unlock the keys.
Press to save data manual-
ly (p. 7).
Press the center key to se-
lect waveform scrolling or
A/B cursor movement, then
press the left and right cur-
sor keys to scroll or move
(p. 12).
Setup and display
Saving operations
Scroll waveforms and
read cursor values
Choose a screen
Start and stop measure-
ment. The LED at the left
lights green while mea-
suring.
Start and stop
measurement
Operating Keys

Operation and Screen Types
3
The screen switches each time you press the key. Operational information is dis-
played along the bottom of the screen.
Waveform Screen Numerical Screen
Waveform/Numerical Screens
Settings Screens
Setting Screen Calc/Save Screen
Comment Screen System Screen
File Screen
Press the left/right
cursor keys to se-
lect between the
Settings screens.

Measurement Procedure
4
Before measuring, be sure to read the "Usage Notes" in the Instruction Manual.
Measurement Procedure
Install the battery pack (option)
Rear View
We recommend using the battery pack to provide backup during power outages,
and to preserve measurement data.
Connect the power cord
Top View
Connect the measurement cable
When using a logic probe
When using a connection
cable or clamp sensor
Top View BNC jack
Logic connector
Insert a CF card (option)
Top View
Confirm that sufficient free space
is available, and for auto-saving,
that a CF card is inserted before
measuring.
Turn the power on
Right Side View

Measurement Procedure
5
Connect to the measurement object
Configure settings for measurement
Select the Setting screen.
• Horizontal axis (Timebase)
• Recording length [Shot]
• Vertical axis (Voltage range)
[Rng/div]
Make other settings as
necessary.
Timebase setting
Settings for CH1
Settings for CH2
Settings for logic
measurements
To record repeatedly with the same
measurement settings:
Trigger mode: [Repeat] (default setting)
Start and finish measuring
Start
Measurement Stop
Measurement
To record once and stop automatically:
Trigger mode: [Single]
Analyze and save

Commercial Power Mains Measurement
6
This procedure records the voltage waveform of 220 V AC
(50/60 Hz) commercial power. The procedure for saving data
after measurement is also described.
In this case, the measurement criterion is specified by a
Level trigger setting.
To measure cyclic waveforms such as that of commercial
mains, the waveform can be best observed by establishing a
specific level as a starting point using Level triggering.
Commercial Power Mains
Measurement
1Prepare the following before measuring
Trigger level
Connect to the
measurement points
Items to prepare
Model 8870-20
AC Adapter (supplied)
Model L9198 Connection
Cord
CF Card
"Measurement Procedure"
(p. 4)
CF card
Connect to CH1
Connect to
power outlet
1
23
5
4
Turn the power on
2Configure measurement settings
Make the following settings on the Measurement Settings screen. 1
2
How to select the timebase
The timebase can be calculated from the frequency and period: f[Hz] =1/t[s] (where fis the fre-
quency and tis the period)
Example: if the measurement frequency is 50 Hz
50 [Hz] = 1/t[s], so t= 1/50 [s] = 0.02 [s] = 20 [ms]
To display five cycles on the screen (which is 20 divisions wide), select the timebase setting
closest to the value calculated as follows: 20 [ms] 5/20 [div] = 5 ms/div.
[Timebase]
Set the time per divi-
sion on the horizontal
axis for viewing the
waveform.
The default settings for the
non-framed items can be
left as-is.
Change as needed.
Select
Apply
[Rng/div]
Setthe voltage perdi-
vision on the vertical
axis.
[Mag] Vertical Axis Magnification
Set the zoom to x1/2 when measur-
ing from 200 to 240 V AC commer-
cial power line.

Commercial Power Mains Measurement
7
In this case, we use the default [Select & Save] method to save waveform data.
Refer to "Analysis" (p. 12) for analysis methods.
3Start and stop measurement
Press the START/STOP key.
“Waiting for trigger” is displayed until the signal
rises above zero volts.
When the measurement criteria are met, trigger-
ing occurs and the waveform is recorded for the
specified duration (Recording Length).
Trigger level
0 V
Trigger slope [ ]
T
In this case, measurement data is 
recorded until you press the START/
STOP key again.
Waiting for trigger
4Save the data
1
2
Displays the Save
dialog.
• To reload data into the instrument or
load it into the Wave Processor pro-
gram, set the Format to Binary.
• To save a screen image (Screen
Shot), display the screen to save, and
press the SAVE key to display the
Save dialog.
• You can confirm the saved data on the
File screen by pressing the FILE key.
(p. 15)
Select
Apply

To Monitor for Abnormal Phenomena
8
This procedure is a method for recording occurrences of volt-
age drop-out phenomena such as occur in a power outage.
During continuous monitoring, measurement data is saved
automatically.
This is an example to record power outage by using voltage
drop trigger. This procedure causes a trigger event when
voltage drops from about 220 Vrms (311 Vpeak) to 198 Vrms
(280 Vpeak) on a 50 Hz commercial power input signal.
To Monitor for Abnormal
Phenomena
1Prepare the following before measuring
Trigger LevelT
½Cycle
Connect to the
measurement points
Items to prepare
Model 8870-20
AC Adapter (supplied)
Model L9198 Connection
Cord
CF Card
"Measurement Procedure"
(p. 4)
CF card
Connect to CH1
Connect to
power outlet
1
23
5
4
Turn the power on
2Configure measurement settings
1
2
With pre-triggering, you specify that waveform recording is to begin just prior
to the occurrence of an anomaly like a momentary interruption.
Pre-triggering is set by specifying the percentage of the overall waveform re-
cording length to be recorded before the trigger point. (For this example,
record 10 divisions of the waveform before any momentary power drop-outs.)
The trigger point is set to 10 divisions of a total recording length of 20 divi-
sions, so set the pre-trigger to 10/20 [div] 100 = 50 [%].
50%
T
20 div
(Recording length)
50%
Select
Apply
Make the following settings on the Measurement Settings screen.
[Timebase]
Set the time per divi-
sion on the horizontal
axis for viewing the
waveform.
[Rng/div]
Set the voltage per di-
vision on the vertical
axis.
[Mag] Vertical Axis Magnification
Set the zoom to x1/2 when measur-
ing from 200 to 240 V AC commer-
cial power line.
The default settings for the
non-framed items can be
left as-is.
Change as needed.

To Monitor for Abnormal Phenomena
9
Refer to "Analysis" (p. 12) for analysis methods.
3Set Auto-save
4Start and stop measurement
Make the following settings on the Calc/Save screen. 1
2
Verify that there is enough space on the CF Card,
and that it is inserted correctly.
Select
Apply
Press the START/STOP key.
A trigger occurs when the commercial mains
voltage falls below 198 Vrms.
After measuring, the measurement data is auto-
matically saved to the CF Card.
After saving, “Waiting for trigger” is displayed
until the next time trigger conditions are met.
In this case, measurement data is 
recorded until you press the START/
STOP key again.
Waiting for
trigger
280 V
-280 V
Trigger Level
½ Cycle
T

To Measure Current
10
Measure current using a clamp sensor.
The Scaling function to convert the voltage input values from
the current sensor into their corresponding current values to
be displayed on screen.
To Measure Current
1Prepare the following before measuring
Trigger Level
T
Connect to the
measurement points
CF cardConnect to CH1
Connect to
power outlet
1
23
54
Turn the
power on
Items to prepare
Model 8870-20
AC Adapter (supplied)
Model 9018-50 Clamp-On
Probe
CF Card
"Measurement Procedure"
(p. 4)
2Configure measurement settings
Make the following settings on the Measurement Settings screen. 1
2
Convert actual input (voltage) values to physical val-
ues, such as of current (using the Scaling function)
When using an optional clamp sensor, a dialog is dis-
played, where you select the Model for the appropriate
Scaling settings. After selecting the model name of the
clamp sensor to be used and the measurement range,
scaling is enabled.
Select
Apply
The default settings for the
non-framed items can be
left as-is.
Change as needed.
[Timebase]
Set the time per divi-
sion on the horizontal
axis for viewing the
waveform.
[Rng/div]
Set the voltage per di-
vision on the vertical
axis.

To Measure Current
11
Refer to "Analysis" (p. 12) for analysis methods.
3Start and stop measurement
Press the START/STOP key.
A trigger event occurs when the signal rises
to the trigger level (5 A), and recording
starts.
In this case, measurement data is 
recorded until you press the START/
STOP key again.
Waiting for trigger
Trigger Level
5 A
0 A
Trigger slope [ ]
T

Analysis
12
Analysis
Viewing a Measurement Waveform
Scrolling the waveform
Earlier Later
The portion of a waveform that is currently
displayed can be confirmed by the position of
the scroll bar.
Whole Waveform
Currently Displayed Portion
Zooming the Waveform View
When the A/B cursors are displayed,
you can use them to zoom in on and
out from the waveform.
Changes the magnification.

Analysis
13
View Measurement Values
2
Press these keys to move the
cursor on the displayed wave-
form. Cursor A moves.
1
Cursor A values
(recording time and
voltage)
Cursor B valuesCursor type
The values at the cursors are
displayed.
Cursor selected to move
When displaying only voltage values
or recording time
You can change the type of cursor to display.
As shipped from the factory, Trace is set to
display recording time and voltage.
Selecting the cursor to move
Select whether to move Cursor A, Cursor B,
or both together.

Analysis
14
Up to four types of calculations can be applied at the same time.
Calculation types: Average, RMS, P-P, maximum, minimum, period and frequency
The following procedure describes how to apply calculations to measured data.
Calculate Measurement Data
Make the following settings on the Calc/Save screen.
1
2
SetNumerical Calculation to ON,andselect up tofourcalculation
types for No. 1 through No. 4.
Select
Apply
Perform the following operation with the Waveform screen displayed.
3
4
Select EXE and press the ENTER
key to display calculation results.
Select
Apply

Analysis
15
Data saved by the 8870-20 can be confirmed on the File screen. It is stored on the
CF Card as follows. The numbers in the file names are automatically generated
sequentially.
View CF Card Contents
HIOKI8870 (Settings data folder)
CONFIG
(Folder for all data other
than settings)
08-05-01(Date)
Moves to
child folder
Moves to
parent folder File
selection
Use to delete or rename a
file
CONFIG0001.SET
WAVE0001.MEM
(Manually saved waveform data, in binary format)
WAVE0001.CSV
(Manually saved waveform data, in text format)
MEAS0001.CSV
(Manually saved numerical calculation results)
SCR0001.BMP
(Manually saved screen image)
AUTO131031 WAVE0003.MEM
(Automatically saved
folder including its cre-
ation time)
Up to 1000 files
WAVE0001.BMP
(Automatically saved
screen image)
LIST0001.BDL
Copy the 8870-20 data to a computer
When the CF Card in the 8870-20 is ac-
cessed from a computer, screens other
than the File screen can be displayed
while not measuring.
While measuring or viewing the File
screen on the 8870-20, it cannot be rec-
ognized by the computer. While con-
nected, files can be copied from the
removable storage media.

Analysis
16