Extech Instruments EX845 User manual

User's Guide
Bluetooth Series 1000 Amp Clamp Meters with IR Thermometer
AC/DC True RMS Clamp meter
Patented

2
Introduction
1000A True RMS AC/DC Current Clamp models measure:
Infrared Temperature
AC/DC Voltage
Resistance
Capacitance
Frequency
Continuity
Diode
Specific functions:
DC Current, True RMS, Type K thermometer, DC Zero
Auto Power OFF
Max/Min recording
Data Hold
Peak Hold
Backlit LCD display
Careful use of this meter will provide many years of reliable service.

3
Safety
International Safety Symbols
This symbol, adjacent to another symbol or terminal, indicates the user must refer to the manual for
further information.
This symbol, adjacent to a terminal, indicates that, under normal use, hazardous voltages may be
present
Double insulation
SAFETY NOTES
•Do not exceed the maximum allowable input range of any function.
•Do not apply voltage to meter when resistance function is selected.
•Set the function switch OFF when the meter is not in use.
•Remove the battery if meter is to be stored for longer than 60 days.
WARNINGS
•Set function switch to the appropriate position before measuring.
•When measuring volts do not switch to current/resistance modes.
•Do not measure current on a circuit whose voltage exceeds 600V.
•When changing ranges always disconnect the test leads from the circuit under test.
•Bluetooth
UL Note
A UL mark does not indicate that this product has been evaluated for accuracy.
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.
Repair or replace any damage before use.
•Use great care when making measurements if the voltages are greater than 25VAC rms or 35VDC.
These voltages are considered a shock hazard.
•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.
Function Maximum Input
A AC, A DC 1000A DC/AC
V DC, V AC 600V DC/AC
Resistance, Capacitance, Frequency, Diode Test 250V DC/AC
Type K Temperature 60V DC, 24V AC

4
Description
eter Description
1. Current clamp
2. Clamp opening trigger
3. Data Hold Button
4. Mode
5. Peak
6. Range
7. DCA Zero
8. MIN/MAX
9. Backlit LCD Display
10. Test lead input jacks
11. IR thermometer and laser pointer (rear)
12. Backlight /BT active / Store trigger button
13. Laser pointer button
14. Function switch
Display icons Description
HOLD Data Hold
Minus sign Negative reading display
0 to 3999 Measurement display digits
ZERO DCA Zero
P Peak value
AUTO Auto Range mode
DC/AC Direct Current / Alternating Current
MAX Max reading
MIN Min reading
Low battery
mV or V Milli-volts or Volts (Voltage)
ΩOhms (Resistance)
A Amperes (Current)
F Farad (Capacitance)
Hz Hertz (Frequency)
oF and oC Fahrenheit and Celsius units (Temperature)
n, m, μ, M, k Unit of measure prefixes: nano, milli, micro, mega, and kilo
•))) Continuity test
Diode test
Laser pointer
BT active

5
Specifications
Function Range & Resolution Accuracy (% of reading + digits)
400.0 AAC ± (2.5% + 8d)
AC Current
50/60 Hz
True RMS 1000 AAC ± (2.8% + 5d)
400.0 ADC ± (2.5% + 5d)
DC Current 1000 ADC ± (2.8% + 5d)
400.0 mVAC ± (1.0% + 10d)
4.000 VAC
40.00 VAC
400.0 VAC
± (1.5% + 5d)
AC Voltage
50/60Hz
True RMS
600 VAC ± (2.0% + 5d)
400.0 mVDC ± (0.8% + 2d)
4.000 VDC
40.00 VDC
400.0 VDC
± (1.5% + 2d)
DC Voltage
600 VDC ± (2.0% + 2d)
400.0Ω± (1.0% + 4d)
4.000kΩ
40.000kΩ
400.0kΩ
± (1.5% + 2d)
4.000MΩ± (2.5% + 3d)
Resistance
40.00MΩ± (3.5% + 5d)
4.000nF ± (5.0% + 30d)
40.00nF ± (5.0% + 20d)
400.0nF
4.000µF
40.00µF
± (3.0% + 5d)
400.0µF ± (4.0% + 10d)
4.000mF ± (10% + 10d)
Capacitance
40.00mF unspecified
4.000kHz ± (1.5% + 2d)
Frequency Sensitivity: 100V (<50Hz); 50V (50 to 400Hz); 5V (401Hz to 4000Hz)

6
Function Range and Resolution Accuracy (% of reading + digits)
-4 to 1400oF ± (3%rdg + 9oF)
Temperature
(type-K) -20 to 760oC ± (3%rdg + 5oC)
-58 to -4°F ±9 °F
-4 to 518°F ±2.0% reading or ±4°F whichever is >
-50 to -20°C ±5°C
Temp (IR)
-20 to 270°C ±2.0% reading or ±2°C
General Specifications
Clamp jaw opening 1.7" (43mm) approx.
Display 3-3/4 digits (4000 counts) backlit LCD
Continuity check Threshold 40Ω; Test current < 0.5mA
Diode test Test current of 0.3mA typical;
Open circuit voltage < 3VDC typical
Low Battery indication Battery symbol is displayed
Over-range indication ‘OL’ display
Measurement rate 2 readings per second, nominal
PEAK Captures peaks >1ms
Thermocouple sensor Type K thermocouple required
IR Spectral response 6 to 16µm
IR Emissivity 0.95 fixed
IR distance ratio 8:1
Input Impedance 10MΩ(VDC and VAC)
AC bandwidth 50 to 400Hz (AAC and VAC)
AC response True rms (AAC and VAC)
Crest Factor 3.0 in 40A and 400A ranges, 1.4 in 1000A range (50/60Hz and 5% to 100% of
range)
Operating Temperature 41°F to 104°F (5°C to 40°C)
Storage Temperature -4°F to 140°F (-20°C to 60°C)
Operating Humidity Max 80% up to 87°F (31°C) decreasing linearly to 50% at 104°F(40°C)
Storage Humidity <80%
Operating Altitude 7000ft. (2000meters) maximum.
Battery One (1) 9V Battery (NEDA 1604)
Auto power OFF After approx. 25 minutes
Dimensions & Weight 10.6x4.3x2” (270x110x50mm); 13.6 oz. (386g)
Safety For indoor use and in accordance with the requirements for double insulation
to IEC1010-1 (2001): EN61010-1 (2001) Overvoltage Category III 600V and
Category II 1000V, Pollution Degree 2.

7
Operation
NOTES: Read and understand all Warning and Caution statements in this operation manual prior to using
this meter. Set the function select switch to the OFF position when the meter is not in use.
AC/DC Current Measurements
WARNING: Ensure that the test leads are disconnected from the meter before making current clamp
measurements.
1. Set the Function switch to the AAC or ADC
range
2. Press the trigger to open jaw. Fully
enclose only one conductor. For
optimum results, center the
conductor in the jaw.
3. The clamp meter LCD will display the
reading.
DCA ZERO
The DC Zero feature removes offset values and
improves accuracy for DC current measurements.
To perform a zero, select ADC and with no
conductor in the jaw:
1. Press the DC ZERO button to zero the
display. “ZERO” will appear in the display. The offset value is now stored andremoved from all measure
ments.
2. To view the stored value, press the DC ZERO button. “ZERO” will flash and the stored value will be
displayed.
3. To exit this mode, press and Hold the ZERO button until “ZERO” is no longer in the display.
AC/DC Voltage Measurements
1. Insert the black test lead into the negative COM terminal and the red test
lead into the positive Vterminal.
2. Set the function switch to the VAC or VDC position.
3. Use the MODE button to select AC or DC Voltage
4. Connect the test leads in parallel to the circuit under test.
5. Read the voltage measurement on the LCD display.

8
Resistance Measurements
Note: Remove power before making resistance measurements
1. Insert the black test lead into the negative COM terminal and the red test lead
into the Ωpositive terminal.
2. Set the function switch to the Ω position.
3. Touch the test probe tips across the circuit or component under test.
4. Read the resistance on the LCD display.
Capacitance Measurements
WARNING: To avoid electric shock, discharge the capacitor under test before
measuring. If “dISC” appears in the display, remove and discharge the
capacitor.
1. Set the function switch to the capacitance position.
2. Insert the black test lead banana plug into the negative COM jack and the r
ed test lead banana plug into the CAP positive jack.
3. Press MODE to zero any stray capacitance.
4. Touch the test probe tips across the part under test.
5. Read the capacitance value in the display.
6. The display will indicate the proper decimal point and value.
Note: For very large values of capacitance measurement time can be several minutes
before the final reading stabilizes.
Frequency Measurements
1. Set the function switch to the V Hz Position.
2. Press and hold the MODE button to select the Frequency (Hz)
function. “k Hz” will appear in the display.
3. Insert the black test lead banana plug into the negative COM jack
and the red test lead banana plug into the Hz positive jack.
4. Touch the test probe tips across the part under test.
5. Read the Frequency value on the display.
6. The display will indicate the proper decimal point and value.
7. Press and hold the MODE button again to return to the voltage mode

9
Type K Temperature Measurements
1. Set the function switch to the KTemp position.
2. Insert the Temperature Probe into the negative COM and the positive
TEMP jacks, observing polarity.
3. Touch the Temperature Probe tip to the device under test.
Continue to touch the part under test with the probe until the reading
stabilizes.
4. Read the temperature on the display. The digital reading will indicate the proper
decimal point and value.
WARNING: To avoid electric shock, be sure the thermocouple probe has been removed
before changing to another measurement function.
Note: An open input or a temperature overrange the meter will display “OL” and beep.
Note: See the “Temperature Units” paragraph to select °F or °C
Continuity Measurements
1. Insert the black test lead into the negative COM terminal and the red test lead into the Ωpositive
terminal.
2. Set the function switch to the •)))position.
3. Use the MODE button to select continuity •))). The display icons will change when the MODE button is
pressed.
4. Touch the test probe tips across the circuit or component under test.
5. If the resistance is < 40Ω, a tone will sound.
Diode Test
1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive jack
2. Turn the function switch to position. Use the MODE button to select the diode function if necessary
(diode symbol will appear on the LCD when in Diode test mode)
3. Touch the test probe tips to the diode or semiconductor junction under test. Note the meter reading
4. Reverse the test lead polarity by reversing the red and black leads. Note this reading
5. The diode or junction can be evaluated as follows:
If one reading displays a value (typically 0.400V to 0.900V) and the other reading displays OL, the
diode is good.
If both readings display OL the device is open.
If both readings are very small or ‘0’, the device is shorted.

10
8”
3”
1”
4”
24”
0.5”
(10cm)
(1.25cm)
(20cm)
(2.5cm)
(60cm)
(7.5cm)
Distance to object
Diameter of spot
Non-Contact InfraRed Temperature Measurements
1. Set the function switch to the IR Temp position.
2. Aim the infrared sensor (rear of the meter) at the
surface to be measured.
3. Press the button in the center of the rotary
function switch to turn on the laser pointer and
identify the surface spot to be measured.
4. The area of the surface to be measured must be larger than the
spot size as determined by the distance to spot size specification.
5. Read the temperature in the display.
Note: See the “Temperature Units” paragraph to select oF or oC
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 8:1 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. The object under test should be larger than the spot (target) size calculated by the field of view diagram.
2. If the surface of the object under test is covered with frost, oil, grime, etc., clean before taking
measurements.
3. If an object's surface is highly reflective, apply masking tape or flat black paint to the surface before
measuring.
4. The meter may not make accurate measurements through transparent surfaces such as glass.
5. Steam, dust, smoke, etc. can obscure measurements.
6. 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.