Extech Instruments 430 User manual

User's Guide
True RMS Multimeter
Extech 430
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com

V01.02.01 7/042
Introduction
Congratulations on your purchase of the Extech 430 (part number
EX430) 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. 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.
This WARNING symbol indicates a potentially
hazardous situation, which if not avoided,
could result in death or serious injury.
This CAUTION symbol indicates a potentially
hazardous situation, which if not avoided, may
result damage to the product.
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)
600 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.
WARNING
CAUTION
MAX
600V

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OVERVOLTAGE CATEGORY III
This meter meets the IEC 610-1-95 standard for
OVERVOLTAGE CATEGORY III. Cat III meters are protected
against overvoltage transients in fixed installation at the
distribution level. Examples include switches in the fixed
installation and some equipment for industrial use with
permanent connection to the fixed installation.
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 Maximum Input
V DC or V AC 1000V DC/750V AC, 200Vrms on
400mV range
mA AC/DC 500mA 250V fast acting fuse
A AC/DC 20A 250V fast acting fuse(30
seconds max every 15 minutes)
Frequency, Resistance,
Capacitance, Duty Cycle,
Diode Test, Continuity
250Vrms for 15sec max
Temperature 60V DC/24V AC
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 battery.
7. NEVER operate the meter unless the back cover and the
battery and fuse covers are in place and fastened securely.

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Controls and Jacks
1. 4000 count LCD display
2. HOLD
3. SELECT button
4. Function switch
5. mA, uA and A input jacks
6. COM input jack
7. Positive input jack
8. RANGE hold button
9. RELATIVE button
10. Backlight button
11. Protective holster
Note: Tilt stand and battery compartment are on rear of unit.
Symbols and Annunciators
•))) Continuity
Diode test
Battery status
Test lead connection
error
n nano (10-9) (capacitance)
µ micro (10-6) (amps, cap)
m milli (10-3) (volts, amps) A Amps
k kilo (103) (ohms) F Farads (capacitance)
M mega (106) (ohms) Ω Ohms
Hz Hertz (frequency) V Volts
% Percent (duty ratio) REL Relative
AC Alternating current AUTO Autoranging
DC Direct current HOLD Display hold
ºF Degrees Fahrenheit ºC Degrees Centigrade

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Specifications
Function Range Resolution Accuracy
400mV 0.1mV ±(0.3% reading + 2 digits)
4V 0.001V
40V 0.01V
400V 0.1V
±(0.5% reading + 2 digits)
DC
Voltage
1000V 1V ±(0.8% reading + 3 digits)
50 to 400Hz 400Hz to 1kHz
400mV 0.1mV ±(1.5% reading
+ 15 digits)
±(2.5% reading
+ 15digits)
4V 0.001V
40V 0.01V
400V 0.1V
±(1.5% reading
+ 6 digits)
±(2.5% reading
+ 8 digits)
AC
Voltage
750V 1V ±(1.8% reading
+ 6 digits)
±(3% reading +
8 digits)
400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
±(1.5% reading + 3 digits)
4A 0.001A
DC
Current
20A 0.01A ±(2.5% reading + 5 digits)
50 to 400Hz 400Hz to 1KHz
400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
±(1.8% reading
+ 8 digits)
±(3.0% reading
+ 7 digits)
4A 0.001A
AC
Current
20A 0.01A
±(3.0% reading
+ 8 digits)
±(3.5% reading
+ 10 digits)
NOTE: Accuracy is stated at 65oF to 83oF (18oC to 28oC) and less
than 75% RH.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com

V01.02.01 7/046
Function Range Resolution Accuracy
400Ω0.1Ω±(0.8% reading + 4 digits)
4kΩ0.001kΩ±(0.8% reading + 2 digits)
40kΩ0.01kΩ
400kΩ0.1kΩ
4MΩ0.001MΩ
±(1.0% reading + 2 digits)
Resistance
40MΩ0.01MΩ±(3.0% reading + 5 digits)
40nF 0.01nF
±(5.0% reading + 7 digits)
400nF 0.1nF ±(3.0% reading + 5 digits)
4µF 0.001µF
40µF 0.01µF ±(3.5% reading + 5 digits)
C
apacitance
100µF 0.1µF ±(5.0% reading + 5 digits)
5.000Hz 0.001Hz
50.00Hz 0.01Hz
±(1.5% reading + 5 digits)
500.0Hz 0.1Hz
5.000kHz 0.001kHz
50.00kHz 0.01kHz
500.0kHz 0.1kHz
±(1.2% reading + 2 digits)
5.000MHz 0.001MHz
10.00MHz 0.01MHz ±(1.5% reading + 4 digits)
Frequency
Sensitivity: 0.8V rms min. @ 20% to 80% duty cycle and
<100kHz; 5Vrms min @ 20% to 80% duty cycle and > 100kHz.
0.1 to 99.9% 0.1% ±(1.2% reading + 2 digits) Duty Cycle
Pulse width: 100µs - 100ms, Frequency: 5Hz to 150kHz
-4 to 1382°F 1°F
Temp
(type-K) -20 to 750°C 1°C
±(3.0% reading + 3 digits)
(probe accuracy not included)
NOTE: Accuracy specifications consist of two elements:
•(% reading) – This is the accuracy of the measurement circuit.
•(+ digits) – This is the accuracy of the analog to digital
converter.

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Diode Test Test current of 0.3mA maximum,
open circuit voltage 1.5V DC typical
Continuity Check Audible signal will sound if the
resistance is less than 150Ω
(approx.), test current <0.7mA
Temperature Sensor Requires type K thermocouple
Input Impedance >7.5MΩ(VDC & VAC)
AC Response True rms
ACV Bandwidth 50Hz to 1kHz
Display 4000 count backlit liquid crystal
Overrange indication “OL” is displayed
Auto Power Off 15 minutes (approximately)
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/250V fast blow
A range; 20A/250V ceramic fast
blow
Operating Temperature 41ºF to 104ºF (5ºC to 40ºC)
Storage Temperature -4oF to 140oF (-20oC to 60oC)
Operating Humidity Max 80% up to 87ºF (31ºC)
decreasing linearly to 50% at
104ºF(40ºC)
Storage Humidity <80%
Operating Altitude 7000ft. (2000meters) maximum.
Weight 0.753lb (342g) (includes holster).
Size 7.36” x 3.2” x 2.0” (187 x 81 x
50mm) (includes holster)
Safety For indoor use and in accordance with
the requirements for double insulation to
IEC1010-1 (1995): EN61010-1 (1995)
Overvoltage Category III 600V and
Category II 1000V, Pollution Degree 2.

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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.
NOTE: On some low AC and DC voltage ranges, with the test
leads not connected to a device, the display may show a
random, changing reading. This is normal and is caused by the
high-input sensitivity. The reading will stabilize and give a proper
measurement when connected to a circuit.
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. Set the function switch to the green
V position.
2. Press the SELECT button to indicate
“DC” on the display.
3. Insert the black test lead banana
plug into the negative COM jack.
Insert the red test lead banana plug
into the positive Vjack.
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.

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AC VOLTAGE MEASUREMENTS
WARNING: Risk of Electrocution. The probe tips may not be
long enough to contact the live parts inside some 240V outlets
for appliances because the contacts are recessed deep in the
outlets. As a result, the reading may show 0 volts when the
outlet actually has voltage on it. Make sure the probe tips are
touching the metal contacts inside the outlet before assuming
that no voltage is present.
CAUTION: Do not measure 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. Set the function switch to the green
V position.
2. Press the SELECT button to indicate
“AC” on the display.
3. Insert the black test lead banana
plug into the negative COM jack.
Insert red test lead banana plug into
the positive Vjack.
4. Touch the black test probe tip to the
neutral side of the circuit.
Touch the red test probe tip to the
“hot” side of the circuit.
5. Read the voltage in the display.

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DC CURRENT MEASUREMENTS
CAUTION: Do not make current measurements on the 20A
scale for longer than 30 seconds. Exceeding 30 seconds may
cause damage to the meter and/or the test leads.
1. Insert the black test lead
banana plug into the negative
COM jack.
2. For current measurements up
to 4000µA DC, set the
function switch to the yellow
µA position and insert the red
test lead banana plug into the
µA/mA jack
3. For current measurements up
to 400mA DC, set the function
switch to the yellow 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 yellow 20A range
and insert the red test lead
banana plug into the 20A jack.
5. Press the SELECT button to indicate “DC” 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.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com