UNI DM-1170A User manual

80000 Counts
Bench Digital Meter DM-1170A
Operation Manual V1.1
BENCHTOP INSTRUMENT

CONTENTS
1. GENERAL INTRODUCTION ........................................................................................................... - 1 -
2. PANEL INSTRUCTIONS ................................................................................................................. - 2 -
3. SPECIAL FUNCTIONS ................................................................................................................... - 6 -
4. MEASUREMENT RANGE............................................................................................................... - 8 -
5. OPERATION INSTRUCTIONS........................................................................................................ - 9 -
6. PROGRAMMABLE CONTROL ..................................................................................................... - 15 -
7. SPECIFICATIONS......................................................................................................................... - 18 -
8. MAINTENANCE ............................................................................................................................ - 21 -
SAFETY INSTRUCTIONS
Highvoltage GND Dualinsulation Refertomanual.
WARNING!
To avoid the electric shock and physical injury, and to avoid possible damage to the meter and the tested
equipments, read this operation manual carefully before using this meter, and follow the following safety
guidelines:
Before use, check and make sure that the instrument’s chassis, the test leads and the insulation layer are
intact.
Use the meter only as specified in this manual. Otherwise, the protection provided by the meter may be
expired.
Never measure voltage while the test leads are plugged into the current input terminals.
Do not input voltage higher than rated voltage between terminals or between terminal and earth (refer
rated voltage to the nearby symbols of ).
Do not use the meter if it looks damaged
Inspect the leads for damaged insulation or exposed metal, check test lead continuity. Replace damaged
leads.
Disconnect the power and discharge all high-voltage capacitors before measurement in resistance,
continuity and diode function.
Be cautious when working at voltage above DC60V or AC42V. Such voltages may cause a shock hazard.
When undertaking measurement, keep your fingers behind the guard’s plant on the test leads or probes.
Select the proper function and measurement range for measurement to avoid damage to the meter.
Disconnect the test leads from the test points before changing to another function.

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1. GENERAL INTRODUCTION
DM-1170A is an intelligent and multi-functional device for various measurements. It features high quality, high
accuracy, high reliability, high frequency measurement and low cost. The meter is in compliance with IEC 6010
CAT II 1000V and CAT III 600V high voltage standards. Other features of this instrument are listed below.
Multi-display: primary 80000 counts, secondary 80000 counts, bar graph 21 segments
50 measuring functions, including basic DCV, ACV, DCA, ACA, Ω, CAP, Hz, TEMP, Diode and
Continuity, etc.
Square waveform output with16 sets of frequency, up to 5kHz, 1%~99% duty cycle
Simultaneous measurements of (AC+DC), (AC+Hz), (DC+dBm), (dBm+Hz), (Hz+Duty), (℃+℉)
Auto data update and refresh, auto data hold, auto peak hold
36 hours dynamic records: MAG, MIN, AVG, MAX-MIN, (REL▲), (REL%)
Measurement with upper/lower limit setting
Timing measurement function
AC measuring adopts highly accurate true RMS measurement, with measurement frequency bandwidth
and AC+DC measuring, capable of accurate true RMS measuring of any waveforms in AC range
RS232 interface for PC remote control
For International Electrical symbols and related symbols used in the meter and operation manual, please refer
to illustrations as below.
AC GND
DC Fuse
AC or DC Square waveform
Low battery Capacitor
Diode Beeper
Double insulation CAUTION! WARNING!
RS232 Communication interface Danger! High Voltage
European standards for
electroma
g
netic compatibilit
y
IEC61010CAT International Electrotechnical
Commission over volta
g
e level
For product improvement, the specifications are subject to change without prior notice.
We hereby will not be responsible for the accident and damage caused by improper operation.
The function stated for this Operation Manual cannot be the reason of special usage.

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2. PANEL INSTRUCTIONS
Fig.2-1 Front panel
1. Power switch 2. Auxiliar
y
ke
y
s3.Terminals
4. Function ke
y
s 5. LCD displa
y
Fig. 2-2 Rear Panel
6. AC110V/220V selector switch 7. Fuse locator
8. Power socket 9. RS232 interface
(
USB adaptor provided
)

-3-
2.1 Power Switch
It turns on or off the meter.
2.2. Auxiliary Keys
Ke
y
Description
SELECT Selects measurement mode.
When using the meter to output square waveform, press SELECT key to change duty
c
y
cle b
y
1%.
RANGE Selects measurement range. The meter is default at auto range mode.
Press this key for at least 2 seconds, the meter returns to auto range.
SET Press this key to set upper limit value, lower limit value and Ref value.
When the SET key is engaged, the RANGE key is used as a moving up key (▲), the
2nd VIEW key as a moving down key (▼), the MAX/MIN as a moving left key (◄),
and REL key as a moving right key (►).
In this case, the RANGE, 2nd VIEW, MAX/MIN and REL keys’ original functions are
disabled. ◄▲▼► keys can be used to enter and adjust the setting values.
MAX/MIN Press this key to enter the dynamic record mode, with maximum record period of 36
hours.
In the dynamic record mode, the meter automatically records the maximum value
(MAX), minimum value (MIN), difference value (MAX-MIN) and calculates the average
value (AVG) of all readings. Press this key to cycle values of MAX, MIN, MAX-MIN,
AVG on the secondary display.

TIMER /
RS232
TIMER
TIMER function is enabled when measurements can be set with REL and MAX/MIN
measuring modes.
Press TIMER key to start the secondary display for counting time. Press TIMER key
again to turn off the counting time display.
When the secondary display is displaying counting time, press key SELECT to enter
Beeper setup for setting up a timer for beeper. Then, press key RANGE (▲), MIX/MIN
(◄), REL (►), 2nd VIEW (▼) to input the time. Next press key TIMER to validate the
new time data. When the counting time exceeds the pre-set time, the beeper sounds.
In the above two modes, press key HOLD to exit timer function and turn off secondary
display, but the preset time remains unchanged.
The time is displayed in the format of “0.00.00” on the secondary display. The max.
counting time is 9h:59m:59s
RS232
Press this key for at least 2 seconds, the RS232 remote control is enabled for PC
control and communication with other instruments. The LCD displays “RS232’
Auto power off function is disabled in RS232 programmable mode.
Press this key for at least 2 seconds again to exit remote control mode and return to
local operation.
HOLD Press this key, the meter enters auto data hold mode and “A-H” is displayed on the
LCD. The data hold mode allows users to hold the displayed value while the analog
bar graph shows the current reading.
In data hold mode, press this key to circle Peak+ hold mode (PH+) and Peak- hold
mode (PH-).
Press this key for at least 2 seconds, the meter exits HOLD mode and return to normal
mode.

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2nd VIEW Selects the secondary display function. In various measuring mode, press 2nd VIEW
key to cycle the displayed data on secondary display.
In square waveform output mode, press 2nd VIEW key to select output frequency
In square waveform output mode, press 2nd VIEW key for at least 2 seconds to
return to 606.10Hz, 50% dut
y
output state.
REL Press this key, the meter enters relative measuring mode and “REL▲” appears on the
LCD display. The relative measuring function measures the difference between the
measurement value and the reference value.
The current reading is used as relative value (Ref) and shown on the secondary
display. Press REL key again, Ref value will be updated by using current reading.
The relative measurement is displayed on primary display in two modes: REL▲or
REL%. Press SELECT key to select “REL▲” or “REL%” mode.
REL▲= measuring value – Reference value
REL% = (REL▲/REL)x100%
“OL” will appear on LCD in the following situation:
When in REL▲mode, the REL▲exceeds measurement range.
When in REL% mode, the REL% exceeds 200% of the REL% value.
When in REL% mode, Ref value is set as 0.
Press REL key for at least 2 seconds to exits reference mode and return to normal
mode.
2.3 Terminals
Terminal Description
COM Common terminal to all measurements
mA Current input terminal for measurement between 0.001mA~800.00mA
20A Current input terminal for measurement between 0.0001A~20.000A
VΩHz
Input terminal for voltage, resistance, continuity, diode, capacitor, frequency,
temperature and duty cycle
Output terminal for square waveform
2.4. Function Keys
Key Description Key Description
V DC voltage OHM Resistance
V AC voltage Diode
mV AC/DC voltage mV TEMP Temperature
mA AC/DC current mA Capacitance
20A AC/DC current 20A Hz/DUTY Frequency/Duty circle
Backlit OUT Square waveform output

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2.5. LCD Display
No. Symbol Description
1 Analog bar graph
2, 3, 17 Negative sign
4 OUT Square waveform output
5 Hi
High frequency measurement
High resistance measurement
Temperature measurement by thermocouple
6 Low battery indication
7 Diode / Audible continuity measurement
8 REL▲% Relative measurement
9, 19 DC, AC, AC+DC DC, AC, AC+DC voltage or current
10 PH+ PH- Positive Peak Hold, Negative Peak Hold
11 A-H Auto Data Hold
12 AVG Average recorded data
13 AUTO Auto range mode
14 APO Auto power off mode
15 RS232 Communication interface
16 MAX/MIN/MAX-MIN MAX Rereading / MIN Reading / MAX-MIN Reading
18, 27 ℉℃ Temperature units and measurement indicator
20 mV/V/mA/A Voltage and current units on secondary display
21 Hz/kHz/MHz/Ω/kΩ/MΩFrequency and resistance units on secondary display
22 %/ %/ ms/ %ms Duty cycle unit and pulse width unit
23 nF/μF Capacitance unit
24 mV/V/mA/A Voltage and current units on primary display
25 dBm dBm annunciation
26 Hz/kHz/MHz/Ω/kΩ/MΩFrequency and resistance units on primary display
28 RPM Round per minute
29 OL Over load symbol, appears when then input value exceeds the rated
value of selected measurement range

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3. SPECIAL FUNCTIONS
3.1 Auto Power Off
When the meter exits RS232 remote control operation mode, the auto power off function is automatically
activated. “APO” appears on the LCD. If there is no operation on any of the keys within 30 minutes, the meter
will be automatically powered off. Five minutes before auto power off, the audible beepers give indication that
the meter is going to be powered off.
When the meter enters RS232 remote control operation mode or dynamic recording mode (MAX/MIN), the
auto power off function is automatically deactivated. When in the above modes, please press POWER switch
to turn off the meter.
3.2 Setting Measurement Upper and Lower Limits
The meter can be set with upper limit (HI) or lower limit (LO), or set upper limit and lower limit (HI-LO) at the
same time.
Set the upper limit (HI) / lower limit (LO):
1) Power on the meter.
2) Press function key to select measurement function.
3) Press RANGE key to select suitable measurement range.
4) Press SET key to enter setting mode.
5) Press SELECT key to select the upper/lower limit setting.
Upper limit setting: “ ” appears on secondary display.
Lower limit setting: “ ” appears on secondary display.
6) Press ◄▲▼► keys to adjust the upper limit value.
7) Press SET key to validate the new input.
Set upper limit and lower limit (HI-LO) at the same time:
1) Power on the meter
2) Press function key to select measurement function.
3) Press RANGE key to select suitable measurement range.
4) Press SET key to enter setting mode.
“ ” appears on secondary display.
5) Press ◄▲▼► keys to adjust the upper limit value.
6) Press SET key to validate the upper limit input.
7) Press SET key to enter setting mode. Then press SELECT key to select the lower setting mode.
“ ” appears on secondary display.
8) Press ◄▲▼► keys to adjust the lower limit value.
Press SET key to validate the lower limit input.
NOTE: Default measurement function is DCV. To enable the upper/lower limits setting in DCV range, another
function must be selected first, then select DCV again.
After setting up the upper and lower limits, measurement can be carried out. The measuring value is displayed
on the primary display, while secondary display will have 3 kinds of displays according to different results:
1) If the measuring value exceeds the upper limit, “ ” appears on the secondary display.
2) If the measuring value exceeds the lower limit, “ ” appears on the secondary display.
3) If the measuring value is between and upper and lower limit, “ ” appears on the secondary display.

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3.3 Setting Measurement Time
Measurement time can be set in all measurement functions except of Diode, Frequency, Temperature and
Square waveform output. Measurement time is displayed on secondary display in the format of “0.00.00”. The
maximum measurement time is 9h.59m.59s.
Follow below steps to set up measurement time:
1) Select a suitable measurement range.
2) Press TIMER key to enter the measurement time setup mode. The secondary display displays “0.00.00”
3) Press SELECT key and the last digit of “0.00.00” on the secondary display glitters, which means this digit
can be adjusted. Use the ◄▲▼► keys to adjust measurement time.
4) Press TIMER key to validate the new setup, and the measurement time is started to calculate immediately.
5) Press TIMER key again to display calculating time on secondary display.
6) When it reaches the measurement time, an indication given by continuous beepers reminds that time is up.
When calculating time is displayed, press SELECT key to switch display of measurement time and calculating
time on secondary display. Measurement time can be adjusted at any point. After measurement time is
adjusted, press TIMER key to validate the new setup. If new enter measurement time is less than calculated
time, indication will be given by continuous beepers immediately.
To stop the beepers, please press HOLD key when calculating time is displayed.
When the timer is activated, the preset measurement time and calculating time are not changed when
measurement functions and operations are changed. Press HOLD key when calculating time is displayed, the
timing function will be stopped and calculating time will be removed. To remove the preset measurement time,
press POWER switch to restart the meter.
3.4 Analog Bar Graph
The function of analog bar graph is imitating the analog needle of the meter but without the overshoot. The bar
graph refreshes data 40 times per second. Because the graph responds 10 times faster than the digital display,
it is widely used in the application of peak value test and zero calibration. It is also commonly used in observing
the rapid variation of input signals.
The bar graph has 21 segments. The number of lit segments is relative to the full-scale value of the selected
range. One unit of the bar graph represents 4000 counts/bar except when in the relative mode. The polarity is
indicated at the left of the bar graph (Positive polarity “+” is not displayed).
3.5 Square Waveform Output
The square waveform output is a very useful function. With adjustable square wave frequency and duty cycle,
users can carry out the pulse wave modulation (PWM) output, and adjust the voltage control, timer control and
clock syntherization.

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4. MEASUREMENT RANGE
A measurement range determines the measuring limits. The meter has several measurement ranges.
1) Select a proper measurement range:
If the selected measurement range is too small (the measurement signal exceeds the measurement range),
the meter will display “OL” on the LCD.
If the selected measurement range is t0o large, the measurement results may have a relatively low
resolution.
2) Auto range and Manual range
The meter has both auto range and manual range for the measurements.
In the AUTO measuring mode, “AUTO” appears on the display. The meter will automatically select a
most suitable range for the measurement signal.
In the MANUAL measuring mode, the measuring range is selected manually by pressing RANGE
key.
If there is more than one range in a measuring function, the meter will default in AUTO range.
3) Enter or exit manual range mode
Press RANGE key to select manual range mode. Then, every press on the RANGE key, the meter
steps to a higher range and will return to the lowest range when the higher range is stepped into.
This allows users to override the auto range and lock the meter in a specific range.
In HOLD or MAX/MIN recording mode, changing the measurement range manually will automatically
exit the HOLD or MAX/MIN mode.
Press RANGE key for at least 2 seconds, the meter returns to AUTO range mode.