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.