Extech Instruments | EX570 | User guide | Extech Instruments EX570 User guide

Extech Instruments EX570 User guide
USER GUIDE
True RMS Multimeter with
IR Thermometer
Model EX570
Introduction
Congratulations on your purchase of the Extech EX570 True RMS Autoranging Multimeter. This meter
measures AC/DC Voltage, AC/DC Current, Resistance, Capacitance, Frequency, Duty Cycle, Diode
Test, and Continuity plus Thermocouple Temperature and InfraRed Temperature. It features a
waterproof, rugged design for heavy duty use. Proper use and care of this meter will provide many
years of reliable service.
Safety
This symbol adjacent to another symbol, terminal or operating device indicates
that the operator must refer to an explanation in the Operating Instructions to
avoid personal injury or damage to the meter.
WARNING
This WARNING symbol indicates a potentially hazardous situation, which if not
avoided, could result in death or serious injury.
CAUTION
This CAUTION symbol indicates a potentially hazardous situation, which if not
avoided, may result damage to the product.
MAX
1000V
This symbol advises the user that the terminal(s) so marked must not be
connected to a circuit point at which the voltage with respect to earth ground
exceeds (in this case) 1000 VAC or VDC.
This symbol adjacent to one or more terminals identifies them as being associated
with ranges that may, in normal use, be subjected to particularly hazardous
voltages. For maximum safety, the meter and its test leads should not be handled
when these terminals are energized.
This symbol indicates that a device is protected throughout by double insulation or
reinforced insulation.
PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY
OVERVOLTAGE CATEGORY I
Equipment of OVERVOLTAGE CATEGORY I is equipment for connection to circuits in which
measures are taken to limit the transient overvoltages to an appropriate low level.
Note – Examples include protected electronic circuits.
OVERVOLTAGE CATEGORY II
Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from
the fixed installation.
Note – Examples include household, office, and laboratory appliances.
OVERVOLTAGE CATEGORY III
Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed installations.
Note – Examples include switches in the fixed installation and some equipment for industrial use
with permanent connection to the fixed installation.
OVERVOLTAGE CATEGORY IV
Equipment of OVERVOLTAGE CATEGORY IV is for use at the origin of the installation.
Note – Examples include electricity meters and primary over-current protection equipment
2
EX570-EU-EN V2.6 1/13
CAUTIONS

Improper use of this meter can cause damage, shock, injury or death. Read and understand
this user manual before operating the meter.

Always remove the test leads before replacing the battery or fuses.

Inspect the condition of the test leads and the meter itself for any damage before operating the
meter.

Use great care when making measurements if the voltages are greater than 25 VAC rms or 35
VDC. These voltages are considered a shock hazard.

Warning! This is a class A equipment. This equipment can cause interferences in the living
quarters; in this case the operator can be required to carry out adequate measures.

Always discharge capacitors and remove power from the device under test before performing
Diode, Resistance or Continuity tests.

Voltage checks on electrical outlets can be difficult and misleading because of the uncertainty
of connection to the recessed electrical contacts. Other means should be used to ensure that
the terminals are not "live".

If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.

This device is not a toy and must not reach children’s hands. It contains hazardous objects as
well as small parts that the children could swallow. In case a child swallows any of them,
please contact a physician immediately

Do not leave batteries and packing material lying around unattended; they can be dangerous
for children if they use them as toys

In case the device is going to be unused for an extended period of time, remove the batteries
to prevent them from draining

Expired or damaged batteries can cause cauterization on contact with the skin. Always,
therefore, use suitable hand gloves in such cases

See that the batteries are not short-circuited. Do not throw batteries into the fire.
3
EX570-EU-EN V2.6 1/13
SAFETY INSTRUCTIONS
This meter has been designed for safe use, but must be operated with caution. The rules listed below
must be carefully followed for safe operation.
1.
NEVER apply voltage or current to the meter that exceeds the specified maximum:
Input Protection Limits
Function
V DC or V AC
Maximum Input
1000 VDC/AC rms
mA AC/DC
500 mA 1000V fast acting fuse
A AC/DC
10A 1000V fast acting fuse (20A for 30 seconds max
every 15 minutes)
Frequency, Resistance, Capacitance,
Duty Cycle, Diode Test, Continuity
1000 VDC/AC rms
Temperature
1000 VDC/AC rms
2.
USE EXTREME CAUTION when working with high voltages.
3.
DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth
ground.
4.
NEVER connect the meter leads across a voltage source while the function switch is in the
current, resistance, or diode mode. Doing so can damage the meter.
5.
ALWAYS discharge filter capacitors in power supplies and disconnect the power when making
resistance or diode tests.
6.
ALWAYS turn off the power and disconnect the test leads before opening the covers to replace
the fuse or batteries.
7.
NEVER operate the meter unless the back cover and the battery and fuse covers are in place
and fastened securely.
8.
If the equipment is used in a manner not specified by the manufacturer, the protection provided
by the equipment may be impaired.
4
EX570-EU-EN V2.6 1/13
Controls and Jacks
2 1
1. IR Thermometer
2. Laser Pointer
3
4
5
6
3. 40,000 count LCD
4. MAX/MIN button
5. MEMORY button
6. SELECT button
7. Function switch
8. mA, µA and 10A input jacks
7
9. PEAK and RELATIVE button
10. RANGE button
11. HOLD and
(Backlight) button
8
12. IR Thermometer button
13. Positive input jack
9
10
11
12
13
14
14. COM input jack
Note: Tilt stand and battery compartment are on rear of unit.
Symbols and Enunciators
•)))
+
MEM
n
µ
m
A
k
F
M

Hz
%
AC
DC
ºF
MAX
Continuity
Diode test
Low Battery
Memory
-9
nano (10 ) (capacitance)
-6
micro (10 ) (amps, cap)
-3
milli (10 ) (volts, amps)
Amps
3
kilo (10 ) (ohms)
Farads (capacitance)
6
mega (10 ) (ohms)
Ohms
Hertz (frequency)
Percent (duty ratio)
Alternating current
Direct current
Degrees Fahrenheit
Maximum
APO
P
V
REL
AUTO
HOLD
ºC
MIN
Auto Power Off
Peak
Volts
Relative
Autoranging
Display hold
Degrees Centigrade
Minimum
5
EX570-EU-EN V2.6 1/13
Operating Instructions
WARNING: Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and
should be measured with great care.
1. ALWAYS turn the function switch to the OFF position when the meter is not in use.
2. If “OL” appears in the display during a measurement, the value exceeds the range you have
selected. Change to a higher range.
AC/DC VOLTAGE MEASUREMENTS
CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or OFF.
Large voltage surges may occur that can damage the meter.
1. Rotate the function switch to the V position.
2. Press the SELECT button to display “DC” or “AC” on the LCD
3. Insert the black test lead banana plug into the negative COM jack. Insert the
red test lead banana plug into the positive V jack.
4. Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.
5. Read the voltage in the display.
DC/AC MILLIVOLT MEASUREMENTS
CAUTION: Do not measure DC/AC voltages if a motor on the circuit is being switched ON or
OFF. Large voltage surges may occur that can damage the meter.
1.
2.
3.
4.
5.
Rotate the function switch to the mV DC-AC position.
Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive V jack.
Press the SELECT button to select “DC” or “AC” millivolts.
Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.
Read the voltage in the display.
6
EX570-EU-EN V2.6 1/13
AC/DC CURRENT MEASUREMENTS
CAUTION: Do not make 20A current measurements for longer than 30 seconds. Exceeding 30
seconds may cause damage to the meter and/or the test leads.
1. Insert black test lead banana plug into the negative COM jack.
2. For current measurements up to 4000µA DC, set the function switch to the µA
position and insert the red test lead banana plug into the µA/mA jack.
3. For current measurements up to 400 mA DC, set the function switch to the mA
position and insert the red test lead banana plug into the µA/mA jack.
4. For current measurements up to 20A DC, set the function switch to the
10A/HZ/% position and insert the red test lead banana plug into the 10A jack.
5. Press the SELECT button to indicate “DC” or “AC” on the display.
6. Remove power from the circuit under test, then open up the circuit at the point
where you wish to measure current.
7. Touch the black test probe tip to the negative side of the circuit. Touch the red
test probe tip to the positive side of the circuit.
8. Apply power to the circuit.
9. Read the current in the display.
RESISTANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all
capacitors before taking any resistance measurements. Remove the batteries and unplug the line
cords.
1. Rotate the function switch to the Ω position.
2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.
3. Press the SELECT button to indicate “”on the display.
4. Touch the test probe tips across the circuit or part under test. It is best to
disconnect one side of the part under test so the rest of the circuit will not
interfere with the resistance reading.
5. Read the resistance in the display.
7
EX570-EU-EN V2.6 1/13
CONTINUITY CHECK
WARNING: To avoid electric shock, never measure continuity on circuits or wires that have
voltage on them.
1. Rotate the function switch to the Ω
position.
2. Insert the black lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive  jack.
3. Press the SELECT button to indicate“
" on the display
4. Touch the test probe tips to the circuit or wire you wish to check.
5. If the resistance is less than approximately 35, the audible signal will sound. If
the circuit is open, the display will indicate “OL”.
DIODE TEST
1. Rotate the function switch to the green Ω
position.
2. Insert the black test lead banana plug into the negative COM jack and the red
test lead banana plug into the positive V jack.
3. Press the SELECT button to indicate “
“ and “V” on the display.
4. Touch the test probes to the diode under test. Forward voltage will typically
indicate 0.400 to 0.700V. Reverse voltage will indicate “OL”. Shorted devices
will indicate near 0V and an open device will indicate “OL” in both polarities.
8
EX570-EU-EN V2.6 1/13
NON-CONTACT INFRARED TEMPERATURE MEASUREMENTS
1.
Rotate the function switch to the IR position.
2.
Press the SELECT button to select °F or °C.
3.
Aim the infrared sensor (top of meter) at the surface to be measured.
4.
Press the IRT
button to turn on the IR thermometer and laser pointer. The laser pointer
identifies the surface spot to be measured.
5.
The area of the surface to be measured must be larger than the spot size as determined by the
distance to spot size specification.
6.
Read the temperature in the display. When the IRT button is released the displayed
temperature will be held for approximately 10 seconds.
WARNING: Do not directly view or direct the laser pointer at an eye. Low power visible lasers
do not normally present a hazard, but may present some potential for hazard if viewed directly for
extended periods of time.
IR Spot to Distance Diagram
The 30:1 spot to distance ratio determines the size of the measured surface area with respect to the
distance the meter is held away from the surface.
IR Measurement Notes
1.
2.
3.
4.
5.
6.
The object under test should be larger than the spot (target) size calculated by the field of view
diagram.
If the surface of the object under test is covered with frost, oil, grime, etc., clean before taking
measurements.
If an object's surface is highly reflective, apply masking tape or flat black paint to the surface
before measuring.
The meter will not make measurements through glass.
Steam, dust, smoke, etc. can obscure measurements.
To find a hot spot, aim the meter outside the area of interest then scan across (in an up and
down motion) until the hot spot is located.
9
EX570-EU-EN V2.6 1/13
THERMOCOUPLE TEMPERATURE MEASUREMENTS
1. Rotate the function switch to the TYPE K position.
2. Insert the Temperature Probe into the input jacks, making sure to observe
the correct polarity.
3. Press the SELECT button to indicate “ºF” or “ºC”
4. Touch the Temperature Probe head to the part whose temperature you
wish to measure. Keep the probe touching the part under test until the
reading stabilizes.
5. Read the temperature in the display.
Note: The temperature probe is fitted with a type K mini connector.
A mini connector to banana connector adaptor is supplied for connection
to the input banana jacks.
Note: The temperature range of the supplied thermocouple probe is -20 to 250°C (-4 to 482°F)
CAPACITANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all
capacitors before taking any capacitance measurements. Remove the batteries and unplug the
line cords.
1. Rotate the function switch to the CAP position.
2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive V jack.
3. Touch the test leads to the capacitor to be tested.
4. Read the capacitance value in the display
FREQUENCY (DUTY CYCLE) MEASUREMENTS
1. Rotate t the function switch to the Hz/% position.
2. Insert the black lead banana plug into the negative COM jack and the red test
lead banana plug into the positive Hz jack.
3. Touch the test probe tips to the circuit under test.
4. Read the frequency on the display.
5. Press the SELECT button to indicate “%”.
6. Read the % duty cycle in the display.
10
EX570-EU-EN V2.6 1/13
MEMORY
The meter can store and recall up to 3 readings.
Storing readings:
1.
Press and Hold the MEM button until “MEM1” (with a flashing 1) appears in the display.
Memory 1 is ready to accept data.
2.
Press and release the MEM button to step through and select memories 2 or 3.
3.
Press and Hold the MEM button to store the displayed value into the memory selected.
4.
After storing the reading, the meter will return to normal operation.
Recalling readings:
1.
Press and release the MEM button. “MEM1” and the stored value will appear in the display.
2.
Press and release the MEM again button to step through and view memories 2 and 3.
3.
Press and release the MEM again button to return to normal operation.
AUTORANGING/MANUAL RANGE SELECTION
When the meter is first turned on, it automatically goes into AutoRanging. This automatically selects
the best range for the measurements being made and is generally the best mode for most
measurements. For measurement situations requiring that a range be manually selected, perform
the following:
1. Press the RANGE key. The “AUTO” display indicator will turn off.
2. Press the RANGE key to step through the available ranges until you select the range you want.
3. To exit the Manual Ranging mode and return to Autoranging, press and hold the RANGE key for
2 seconds.
Note: Manual ranging does not apply for the Temperature functions.
MAX/MIN
1. Press the MAX/MIN key to activate the MAX/MIN recording mode. The display icon "MAX" will
appear. The meter will display and hold the maximum reading and will update only when a new
“max” occurs.
2. Press the MAX/MIN key again and the display icon "MIN" will appear. The meter will display and
hold the minimum reading and will update only when a new “min” occurs.
3. Press the MX/MIN key once more and the icon "AVG" will appear. The meter will display the
average reading since the meter was powered on.
4. To exit MAX/MIN mode press and hold the MAX/MIN key for 2 seconds.
11
EX570-EU-EN V2.6 1/13
Relative mode
The relative measurement feature allows you to make measurements relative to a stored reference
value. A reference voltage, current, etc. can be stored and measurements made in comparison to
that value. The displayed value is the difference between the reference value and the measured
value.
1. Perform the measurement as described in the operating instructions.
2. Press and Hold the REL button to store the reading in the display and the "REL" indicator will
appear on the display.
3. The display will now indicate the difference between the stored value and the measured value.
4. Press and Hold the REL button to exit the relative mode.
PEAK HOLD
The Peak Hold function captures the peak AC voltage or current. The meter can capture negative or
positive peaks as fast as 1 millisecond in duration. Press the PEAK button. “PMAX” will appear in
the display. The meter will update the display each time a higher positive peak occurs. Press the
PEAK button again to exit the mode.
DISPLAY BACKLIGHT
key for >1 second to turn the backlight on. The backlight will automatically turn
Press the HOLD/
off after 10 seconds.
HOLD
The hold function freezes the reading in the display. Press the HOLD key momentarily to activate or
to exit the HOLD function.
LOW BATTERY INDICATION
When the low battery
+
icon appears in the display, the battery should be replaced.
AUTO POWER OFF
The auto off feature will turn the meter off after 15 minutes. To disable the auto power off feature,
hold down the SELECT button and turn the meter on. “APO d” will appear in the display. Turn the
meter off and then on again to re-enable the auto power off feature.
12
EX570-EU-EN V2.6 1/13
Maintenance
WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before
removing the back cover or the battery or fuse covers.
WARNING: To avoid electric shock, do not operate your meter until the battery and fuse covers are
in place and fastened securely.
This MultiMeter is designed to provide years of dependable service, if the following care instructions
are performed:
1. KEEP THE METER DRY. If it gets wet, wipe it off.
2. USE AND STORE THE METER IN NORMAL TEMPERATURES. Temperature extremes can
shorten the life of the electronic parts and distort or melt plastic parts.
3. HANDLE THE METER GENTLY AND CAREFULLY. Dropping it can damage the electronic parts
or the case.
4. KEEP THE METER CLEAN. Wipe the case occasionally with a damp cloth. DO NOT use
chemicals, cleaning solvents, or detergents.
5. USE ONLY FRESH BATTERIES OF THE RECOMMENDED SIZE AND TYPE. Remove old or
weak batteries so they do not leak and damage the unit.
6. IF THE METER IS TO BE STORED FOR A LONG PERIOD OF TIME, the batteries should be
removed to prevent damage to the unit.
BATTERY INSTALLATION
WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before
removing the battery cover.
1. Turn power off and disconnect the test leads from the meter.
2. Open the rear battery cover by removing two screws (B) using a Phillips head screwdriver.
3. Insert the battery into battery holder, observing the correct polarity.
4. Put the battery cover back in place. Secure with the screws.
All EU users are legally bound by the Battery Ordinance to return all used batteries to
community collection points or wherever batteries / accumulators are sold.
Disposal in household trash or refuse is prohibited.
Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the
end of its lifecycle
Other Battery Safety Reminders

Never dispose of batteries in a fire. Batteries may explode or leak.

Never mix battery types. Always install new batteries of the same type.
WARNING: To avoid electric shock, do not operate the meter until the battery cover is in place and
fastened securely.
NOTE: If your meter does not work properly, check the fuses and batteries to make sure that they are
still good and that they are properly inserted.
13
EX570-EU-EN V2.6 1/13
REPLACING THE FUSES
WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before
removing the meter cover.
A
B
A
B
A
F1 F2
1. Disconnect the test leads from the meter.
2. Remove the battery cover (two “B” screws) and the battery.
3. Remove the six “A” screws securing the rear cover.
4. Gently remove the old fuse and install the new fuse into the holder.
5. Always use a fuse of the proper size and value (0.5A/1000V fast blow for the 600 mA range [SIBA
70-172-40], 10A/1000V fast blow for the 10A range [SIBA 50-199-06]).
6. Replace and secure the rear cover, battery and battery cover.
WARNING: To avoid electric shock, do not operate your meter until the fuse cover is in place and
fastened securely.
14
EX570-EU-EN V2.6 1/13
Specifications
Function
Range
Resolution
DC Voltage
400 mV
0.01 mV
4V
0.0001V
40V
0.001V
Accuracy
(0.06% reading + 2 digits)
400V
0.01V
1000V
0.1V
400 mV
0.01 mV
4V
0.0001 V
40 V
0.001 V
400 V
0.01 V
1000 V
0.1 V
AC Voltage
40 Hz to 65 Hz
66 Hz to 1000 Hz
(0.5% rdg + 3 digits)
(1% rdg + 3 digits)
All AC voltage ranges are specified from 5% of range to 100% of range
DC Current
400A
0.01 A
4000A
0.1 A
40mA
0.001 mA
400mA
0.01 mA
(1.0% reading + 3 digits)
10A
0.00 A
(1.5% reading + 3 digits)
(0.7% reading + 3 digits)
(20 A: 30 sec max with reduced accuracy)
AC Current
400A
0.01 A
4000A
0.1 A
40mA
0.001 mA
400mA
0.01 mA
10A
0.001 A
40 Hz to 65 Hz
66 Hz to 1000 Hz
(1.0% rdg + 3 digits)
(1.5% rdg + 3 digits)
(2.0% reading + 3
digits)
(2.0% reading + 3
digits)
(20A: 30 sec max with reduced accuracy)
o
o
o
o
NOTE: Accuracy is stated at 18 C to 28 C (65 F to 83 F) and less than 75% RH.
15
EX570-EU-EN V2.6 1/13
Function
Range
Resolution
Resistance
400 
0.01 
4 k
0.0001 k
40 k
0.001 k
400 k
0.01 k
4 M
0.0001 M
40 M
0.001 M
40 nF
0.001 nF
400 nF
0.01 nF
Capacitance
Frequency
Duty Cycle
4 µF
0.0001 µF
40 µF
0.001 µF
400 µF
0.01 µF
4000 µF
0.1 µF
40000 F
1 µF
40 Hz
0.001 Hz
400 Hz
0.01 Hz
4 kHz
0.0001 kHz
40 kHz
0.001 kHz
400 kHz
0.01 kHz
4 MHz
0.0001 MHz
40 MHz
0.001 MHz
0.1 to 99.90%
Accuracy
(0.3% reading + 4 digits)
(2.0% reading + 20 digits)
(3.5% reading + 40 digits)
(5% reading + 10 digits)
(0.1% reading + 1 digits)
(1.0% reading + 2 digits)
0.01%
Pulse width: 100 µs – 100 ms, Frequency: 5 Hz to 150 kHz
Temperature
-50 to 1382F
1F
(type-K)
-45 to 750C
1C
(1.0% reading + 4.5°F)
(1.0% reading + 2.5°C)
(probe accuracy not included)
Temperature IR
-30 to -5C
4C
-6 to -100C
 2C
101 to 550C
-22 to 23F
(2.0%rdg + 2C)
1C/F
 8F
24 to 212°F
 4°F
213 to 1022°F
(2.0%rdg + 4F)
16
EX570-EU-EN V2.6 1/13
Enclosure
Diode Test
Continuity Check
Double molded, Waterproof (IP64)
Test current of 0.9mA maximum, open circuit voltage 2.8V DC typical
Audible signal will sound if the resistance is less than 35 (approx.), test
current <0.35mA
PEAK
Captures peaks >1ms
Memory
Store and recall up to 3 values
Temperature Sensor
Requires type K thermocouple
Input Impedance
>10MΩ VDC & >3MΩ VAC
AC Response
True rms
ACV Bandwidth
40Hz to 1000Hz
IR Spectral response
6 to 16µm
IR Emissivity
0.95 fixed
IR distance ratio
30:1
Laser pointer
Class 2 laser < 1mW power; Wavelength is 630 to 670nm
Crest Factor
≤3 at full scale up to 500V, decreasing linearly to ≤1.5 at 1000V
Display
40,000 count backlit liquid crystal display with bargraph
Overrange indication
“OL” is displayed
Auto Power Off
15 minutes (approximately) with disable feature
Polarity
Automatic (no indication for positive); Minus (-) sign for negative
Measurement Rate
2 times per second, nominal
Low Battery Indication “ + ” is displayed if battery voltage drops below operating voltage
Battery
One 9 volt (NEDA 1604) battery
Fuses
mA, µA ranges; 0.5A/1000V ceramic fast blow
A range; 10A/1000V ceramic fast blow
Operating Temperature 5ºC to 40ºC (41ºF to 104ºF)
o
o
o
o
Storage Temperature
-20 C to 60 C (-4 F to 140 F)
Operating Humidity
Max 80% up to 31ºC (87ºF) decreasing linearly to 50% at 40ºC (104ºF)
Storage Humidity
<80%
Operating Altitude
2000 meters (7000 ft) maximum
Weight
342 g (0.753 lb) (includes holster)
Size
187 x 81 x 50 mm (7.36” x 3.2” x 2.0”) (includes holster)
Safety
This meter is intended for origin of installation use and protected, against
nd
the users, by double insulation per EN61010-1 and IEC61010-1 2 Edition
(2001) to Category IV 600V and Category III 1000V; Pollution Degree 2.
Approvals
CE
Copyright © 2012 FLIR Systems, Inc.
All rights reserved including the right of reproduction in whole or in part in any form
ISO-9001 Certified
www.extech.com
17
EX570-EU-EN V2.6 1/13
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising