THE STANDARD IN PRECISION MEASUREMENT
User Manual
Industrial IP67-Rated Digital Multimeters
with NIST-Traceable Calibration
Model 20250-53
(4000 Count)
Model 20250-54
(4000 Count, True RMS)
1065DGMAN_20250-53-54 Manual.indd 1 8/16/2017 10:42:05 AM
Introduction
Digi-Sense Industrial Digital Multimeters (model 20250-53;
TRMS model 20250-54) are a must-have on your electrical
tool belt—especially for those who need a rugged and
reliable meter. These versatile and simple-to-use units safely
measure the full range of common parameters including voltage,
current, resistance, capacitance, frequency, temperature, and
more. All this technology is packaged in a double-insulated
housing that meets IP67 requirements. The instruments are fully
tested and calibrated to NIST-traceable standards. Careful use of
the meter will provide years of reliable service.
Safety
Safety Warnings
The following safety information must be
observed to insure maximum personal safety
during the operation at this meter:
• Measurements beyond the maximum selected range
must not be attempted.
• Extreme care must be taken when measuring above 50 V,
especially on live bus-bars.
• To measure voltage, the instrument must not be switched
to a current or resistance range, or to the diode check or
buzzer position.
• Circuits must be de-energized and isolated before
carrying out resistance tests.
• The rotary function switch must only be turned after
removing test connections.
• All external voltages must be disconnected from the
instrument before removing the battery.
2
1065DGMAN_20250-53-54 Manual.indd 2 8/16/2017 10:42:05 AM
• Test leads and prods must be in good order, clean, and
MAX
with no broken or cracked insulation.
• UK Safety Authorities recommend the use of fused test
leads when measuring voltage on high energy systems.
• Replacement fuses must be of the correct type and rating.
• The instrument must not be used if any part of it is damaged.
• Warnings and precautions must be read and understood
before an instrument is used. They must be observed during the operation of this instrument.
Safety used on this instrument are:
Caution: refer to accompanying notes.
This symbol indicates that the operator must refer
to an explanation in the manual to avoid personal
injury or damage to the meter.
Caution: risk of electric shock
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) 1000 VAC or VDC.
Equipment protected throughout by Double
Insulation (Class II)
Equipment complies with current EU directives.
1065DGMAN_20250-53-54 Manual.indd 3 8/16/2017 10:42:05 AM
3
Unpacking
Check individual parts against the list of items below. If anything is
missing or damaged, please contact your instrument supplier
immediately.
1. Instrument
2. Test leads
3. One type K temperature probe (model 20250-54 only)
4. One 9 V battery
5. Carrying case
6. User manual
7. NIST-traceable calibration report with data
Meter Description (Model 20250-53)
1. NCV detection light
2. LCD with symbols
3. RANGE button
4. REL (Relative) button
5. MODE button
6. Rotary function switch
7. 10A (positive) jack
8. µA/mA jack
9. Hz% button
10. Data HOLD button
11. Backlight button
12. V Ω CAP •))) Hz% jack
13. COM (negative) jack
14. Tilt stand and battery
compartment are on
rear of unit
4
1
9
2
3
4
5
6
7
8
10
11
12
13
14
1065DGMAN_20250-53-54 Manual.indd 4 8/16/2017 10:42:05 AM
Meter Description (Model 20250-54)
1. NCV detection light
2. LCD with symbols and
analog bar graph
3. Data HOLD button
4. RANGE button
5. MODE button
6. Rotary function switch
7. 10A (positive) jack
1
2
3
4
5
8. µA/mA jack
9. MAX/MIN button
10. PEAK button
11. Backlight button
12. V Ω CAP •))) Hz
Temp jack
6
7
8
13. COM (negative) jack
14. Tilt stand and battery
compartment are on rear of unit
Symbols and Annunciators
Continuity
•)))
Low battery
Diode test
HOLD Data HOLD
AUTO Autoranging
AC Alternating Current or Voltage
DC Direct Current or Voltage
V Volts
A, mA, µA Current range
9
10
11
12
13
14
5
1065DGMAN_20250-53-54 Manual.indd 5 8/16/2017 10:42:05 AM
Setup and Operation
To turn on the instrument turn the rotary function switch
from the OFF position to any measurement range.
NOTE: For best battery life ALWAYS turn the rotary function
switch to the OFF position when the meter is not in use.
Meter has Auto power-off that automatically shuts the
meter off if 30 minutes elapse between uses.
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.
MODE Button
To select AC or DC measurement when Voltages, Amps,
mA , µA, Ω,
HOLD Button
The Data HOLD function allows the meter to "freeze" a
measurement for later reference.
1. Press the HOLD button to “freeze” the reading on the
display. The indicator “HOLD” will be appear in the
display.
2. Press the HOLD button to resume normal operation.
, •))), CAP, or Hz% are selected.
6
1065DGMAN_20250-53-54 Manual.indd 6 8/16/2017 10:42:05 AM
RANGE Button
When the meter is rst turned on, it automatically defaults
to Autoranging. This automatically selects the best range
for the measurements being made and is generally the
optimal mode for most measurements. For measurement
situations requiring that a range be manually selected,
perform the following:
1. Press the RANGE button. The “Auto Range” display
indicator will turn off. The “Manual Range” display
indicator will turn on
2. Press the RANGE button to step through the available
ranges until you select the range you want.
3. Press and hold the RANGE button for 2 seconds to exit
the manual ranging mode and return to autoranging.
REL Button (Model 20250-53 only)
The relative (REL) 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.
Note: This function works with all functions except Hz%,
Diode, and Continuity.
1. Press the REL button to store the reading in the display
and the "REL" indicator will appear on the display.
2. The display will now indicate the difference between the
stored value and the measured value.
3. Press the REL button again to resume normal operation.
1065DGMAN_20250-53-54 Manual.indd 7 8/16/2017 10:42:05 AM
7
MAX/MIN Button (Model 20250-54 only)
The MAX/MIN function allows the meter to capture the
highest or lowest reading for later reference.
1. Press the MAX/MIN button to begin measurement. The
indicator “MAX” or “MIN” will appear in the display.
2. If the “MAX MIN” messages are ashing, the instrument
is in MAX/MIN mode but not recording, press the
MAX/MIN button to select a mode.
3. To resume operation, hold down the MAX/MIN button
for 2 seconds.
PEAK Hold Button (Model 20250-54 only)
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.
1. Set the rotary function switch to the A or V position.
2. Press the MODE button to select “AC”.
3. Allow time for the display to stabilize.
4. Press and hold the PEAK button until “CAL” appears in
the display.
5. This procedure will zero the range selected.
6. Press the PEAK button; the indicator “Pmax” will be
displayed.
7. The display will update each time a higher positive peak
occurs.
8. Press the PEAK button again; the indicator “Pmin” will
be displayed. The display will now update and indicate
the lowest negative peak.
8
1065DGMAN_20250-53-54 Manual.indd 8 8/16/2017 10:42:05 AM
9. To return to normal operation, press and hold the PEAK
button until the “Pmax” or “Pmin” indicator switches
off.
10. If the rotary function switch position is changed after a
calibration, the PEAK Hold calibration must be repeated
for the new function selected.
BACKLIGHT Button
1. Press the BACKLIGHT button to switch on the display
light.
2. Press BACKLIGHT button again to exit the light mode.
AC and DC Voltage Measurements
1. Insert the black test lead into the negative COM terminal
and the red test lead into the positive V terminal.
2. Set the rotary function switch to the V AC/DC position.
3. Press 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 display.
AC and DC Current Measurements
1. Insert the black test lead banana plug into the negative
COM jack.
2. For current measurements up to 4000 µA, set the rotary
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, set the rotary
function switch to the mA range and insert the red test
lead banana plug into the (µA, mA) jack.
1065DGMAN_20250-53-54 Manual.indd 9 8/16/2017 10:42:05 AM
9
4. For current measurements up to 10 A, set the rotary
function switch to the 10A position and insert the red
test lead banana plug into the 10A jack.
5. Press the MODE button to select “AC” or “DC” current.
6. Remove power from the circuit under test, then open 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 and touch the red test probe tip to the positive
side of the circuit.
8. Apply power to the circuit.
9. Read the current measurement on display. The proper
decimal point, value, and symbol will be indicated.
Resistance Measurement
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. Set the rotary function switch to the Ω position.
2. Insert the black test lead plug into the negative COM
socket and the red test lead plug into the positive Ω jack.
3. Press the MODE button until “Ω” appears in 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 measurement on the display. The
display will indicate the proper decimal point, value, and
symbol.
10
1065DGMAN_20250-53-54 Manual.indd 10 8/16/2017 10:42:05 AM
Continuity Check
WARNING: To avoid electric shock, never measure
continuity on circuits or wires that have voltage on
them.
1. Set the rotary function switch to the •))) position.
2. Insert the black lead plug into the COM socket and the
red test lead plug into the positive •))) socket.
3. Press the MODE button until “•)))” appears in the display.
4. Touch the test probe tips to the circuit or wire you wish
to check.
5. If the resistance is less than 50 Ω (20250-53) or 35 Ω
(20250-54), the audible signal will sound. The display will
also show the actual resistance in ohms.
Diode Test
WARNING: To avoid electric shock, do not test any
diode that has voltage on it.
1. Set the rotary function switch to the
position.
2. Insert the black test lead plug into the COM socket and
the red test lead plug into the
3. Press the MODE button until “
socket.
” appears in the display.
4. Touch the test probe tips to the diode or semiconductor
junction you wish to test. Note the meter reading.
5. Reverse the probe polarity by switching probe position.
Note this reading.
1065DGMAN_20250-53-54 Manual.indd 11 8/16/2017 10:42:05 AM
11
6. The diode or junction can be evaluated as follows:
a. If one reading shows a value and the other reading
shows “OL”, the diode is good.
b. If both readings show “OL”, the device is open.
c. If both readings are very small or zero, the device is
shorted.
NOTE: The value indicated in the display during the
diode check is the forward voltage.
Capacitance Measurement
WARNING: To avoid electric shock, discharge the
capacitor under test before measuring.
1. Set the rotary function switch to the CAP position.
2. If needed, press the MODE button until “nF” appears 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
CAP positive jack.
4. Touch the test probe tips across the part under test.
5. Read the capacitance value in the display. 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 nal reading stabi-
lizes. The bar graph is disabled in capacitance measurement
mode. The LCD displays “DIS. C”. Discharging through the
chip is quite slow. We recommend that the user discharge the
capacitor with some other apparatus.
12
1065DGMAN_20250-53-54 Manual.indd 12 8/16/2017 10:42:05 AM
Frequency or % Duty Cycle Measurements
(Model 20250-53 only)
1. Set the rotary function switch to the Hz% position.
2. Press the Hz% button to indicate “Hz” in the display.
3. Insert the black lead banana plug into the negative COM jack
and the red test lead banana plug into the positive Hz jack.
4. Touch the test probe tips to the circuit under test.
5. Press the Hz% button again to indicate “%” on the
display. Read the % of duty cycle on the display.
Frequency Measurement (Model 20250-54 only)
1. Set the rotary function switch to the Hz position.
2. Insert the black test 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 in the display. The digital reading
will indicate the proper decimal point, symbols (Hz, kHz,
MHz), and value.
Temperature Measurement (Model 20250-54 only)
1. Set the rotary function switch to the Temp °C or Temp °F
position.
2. Insert the temperature probe into the input jacks, making
sure to observe the correct polarity.
3. Touch the probe head to the part whose temperature
you wish to measure. Keep the probe touching the part
under test until reading stabilizes (about 30 seconds).
4. Read the temperature measurement on the display.
1065DGMAN_20250-53-54 Manual.indd 13 8/16/2017 10:42:05 AM
13
Note: The temperature probe is tted with a type K mini
connector. A mini connector to banana connector adapter
is supplied for connection to the input banana jacks.
Noncontact Voltage Detection
The noncontact voltage (NCV) function works on any rotary
function switch position.
1. Test the detector on a known live circuit before use.
2. Hold the top of the meter very close to the voltage
source as shown.
3. If voltage is present, the NCV indicator light above the
LCD will ash a bright red.
Specifications
Accuracy is given at 65 to 83°F (18 to 28°C), less than 70% RH.
DC Voltage (Autoranging)
Range Resolution Accuracy
20250-53 20250-54 20250-53 20250-54 20250-53 20250-54
400.0 mV 400.0 mV 0.1 mV 0.1 mV
4.000 V 4.000 V 1 mV 1 mV
40.00 V 40.00 V 10 mV 10 mV
400.0 V 400.0 V 100 mV 100 mV
1000 V 1000 V 1 V 1 V
Input impedance: 10 MΩ
Maximum input: 1000 V DC
±1.2% rdg
± 2 dgts
±1.2% rdg
± 4 dgts
±0.8% rdg
± 2 dgts
±1% rdg
± 2 dgts
14
1065DGMAN_20250-53-54 Manual.indd 14 8/16/2017 10:42:05 AM
AC Voltage (Autoranging)
Range Resolution Accuracy
20250-53 20250-54 20250-53 20250-54 20250-53 20250-54
400.0 mV 400.0 mV 0.1 mV 0.1 mV
4.000 V 4.000 V 1 mV 1 mV
40.00 V 40.00 V 10 mV 10 mV
400.0 V 400.0 V 100 mV 100 mV
1000 V 1000 V 1 V 1 V
±1.5% rdg
± 3 dgts
±1.5% rdg
± 5 dgts
±1.0% rdg
± 3 dgts
±1.2% rdg
± 5 dgts
Input impedance: 10 MΩ
AC response: 50 to 400 Hz
Maximum input: 1000 V AC RMS
DC Current (Autoranging)
Range Resolution Accuracy
20250-53 20250-54 20250-53 20250-54 20250-53 20250-54
400.0 µA 400.0 µA 0.1 µA 0.1 µA
4000 µA 4000 µA 1 µA 1 µA
40.00 mA 40.00 mA 10 µA 10 µA
400.0 mA 400.0 mA 100 µA 100 µA
10 A 10 A 10 mA 10 mA
Overload protection: FF500mA / 1000V and F10A / 1000V fuse
Maximum input: 400 µA DC on µA range, 400 mA DC on mA range,
10 A DC on 10 A range
±1.2% rdg
± 3 dgts
±2.5% rdg
± 3 dgts
±1.2% rdg
± 5 dgts
±1.5% rdg
± 5 dgts
1065DGMAN_20250-53-54 Manual.indd 15 8/16/2017 10:42:06 AM
15
AC Current (Autoranging)
Range Resolution Accuracy
400.0 µA 400.0 µA 0.1 µA 0.1 µA
4000 µA 4000 µA 1 µA 1 µA
40.00 mA 40.00 mA 10 µA 10 µA
400.0 mA 400.0 mA 100 µA 100 µA
10 A 10 A 10 mA 10 mA ±3.0% rdg ± 7 dgts ±1.8% rdg ± 5 dgts
±1.5% rdg ± 5 dgts ±1.2% rdg ± 5 dgts
Overload protection: FF500mA / 1000V and F10A / 1000V fuse
Frequency range: 50 to 400 Hz
Maximum input: 400 µA AC RMS on µA range, 400 mA AC RMS
on mA range, 10 A AC RMS on 10 A range
Resistance (Autoranging)
Range Resolution Accuracy
20250-53 20250-54 20250-53 20250-53 20250-54 20250-53
400.0 Ω 400.0 Ω 0.1 Ω 0.1 Ω
4.000 kΩ 4.000 kΩ 1 Ω 1 Ω
40.00 kΩ 40.00 kΩ 10 Ω 10 Ω
400.0 kΩ 400.0 kΩ 100 Ω 100 Ω
4.000 MΩ 4.000 MΩ 1 kΩ 1 kΩ
40.00 MΩ 40.00 MΩ 10 kΩ 10 kΩ
±1.2% rdg
± 5 dgts
±1.0% rdg
± 2 dgts
±2.5% rdg
± 8 dgts
±0.8% rdg
± 5 dgts
±0.8% rdg
± 2 dgts
±2.5% rdg
± 8 dgts
Input protection: 1000 V DC or 1000 V AC RMS
Capacitance (Autoranging)
Range Resolution Accuracy
40.00 nF 10 pF ±5.0% rdg ± 7 dgts
400.0 nF 0.1 nF
4.000 µF 1 nF
40.00 µF 10 nF
400.0 µF 0.1 µF
4.000 mF 1 µF
40.00 mF 10 µF
Input protection: 1000 V DC or 1000 V AC RMS
±3.0% rdg ± 5 dgts
±5.0% rdg ± 7 dgts
1065DGMAN_20250-53-54 Manual.indd 16 8/16/2017 10:42:06 AM
16
Frequency (Autoranging)
Range Resolution Accuracy
4.000 Hz 0.001 Hz
40.00 Hz 0.01 Hz
400.0 Hz 0.1 Hz
4.000 kHz 1 Hz
40.00 kHz 10 Hz
400.0 kHz 100 Hz
10.00 MHz 1 kHz ±1.2% rdg ± 4 dgts
±1.0% rdg ± 3 dgts
Sensitivity: >0.5 V RMS while ≤1 MHz; >3 V RMS while >1 MHz
Overload protection: 1000 V DC or 1000 V AC RMS
Temperature (Model 20250-54 only)
Range Resolution Accuracy
–4 to 1400°F 1°F ±3% rdg ± 8 dgts
–20 to 760°C 1°C ±3% rdg ± 5 dgts
Sensor: type K thermocouple
Overload protection: 1000 V DC or AC RMS
Diode Test
Test current Resolution Accuracy
1 ma typical, open max 0.3 V 1 mV ±10% rdg ± 5 dgts
Open circuit voltage: max 0.3 V DC
Overload protection: 1000 V DC or AC RMS
Audible Continuity
Audible threshold: Less than 50 Ω (20250-53),
35 Ω (20250-54); Test current max 1.5 mA
Overload protection: 1000 V DC or AC RMS
Compliance: IEC/EN 61010-1:2001 and IEC/EN 61010-031:2002
Insulation: Class 2, Double insulation
1065DGMAN_20250-53-54 Manual.indd 17 8/16/2017 10:42:06 AM
17
Overvoltage category: CAT IV 600 V, CAT III 1000 V
NOTE: These meters meet CAT III and CAT IV IEC 61010 standards.
The IEC 61010 safety standard denes four overvoltage categories
(CAT I to IV) based on the magnitude of danger from transient
impulses. CAT III meters are designed to protect against transients in
xed-equipment installations at the distribution level; CAT IV meters
are designed to protect against transients from the primary
supply level (overhead or underground utility service).
Max voltage between any terminal and earth ground:
1000 V DC/AC RMS
Display: 4000 count LCD, 13⁄16" (21 mm) high
Polarity: Automatic, (–) negative polarity indication
Overrange indication: “OL” mark indication is displayed
Low-battery indication: Battery symbol “ ” is displayed
Measurement rate: 2 times per second nominal
Operating environment: 14 to 122°F (–10 to 50°C) at <70% RH
Storage temperature: –4 to 140°F (–20 to 60°C) at <80% RH
Relative humidity: 90% (0 to 30°C); 75% (30 to 40°C);
45% (40 to 50°C)
For inside use, max height: Operating: 9842 ft (3000 m), Storage
32,808 ft (10,000 m)
Pollution degree: 2
Power: One 9 V battery, NEDA 1604, IEC 6F22
Auto power-off: Approximately after 30 minutes
of inactivity
Weight: 13 oz (375 g)
Dimensions: 73⁄16" x 31⁄4" x 23⁄16" (18.2 x 8.2 x 5.5 cm)
1065DGMAN_20250-53-54 Manual.indd 18 8/16/2017 10:42:06 AM
18
Maintenance, Recalibration, and Repair
Cleaning and Storage
• Clean meter with a damp cloth and mild detergent when
necessary. Do not use solvents or abrasives.
• Store the meter in an area with moderate temperature
and humidity.
Battery Replacement
WARNING: To avoid electric shock, disconnect the
test leads from any source of voltage before removing the battery door.
1. When the battery becomes exhausted or drops below
operating voltage, the battery warning symbol will
appear in the right-hand side of the LCD. The battery
should be replaced.
2. Disconnect the test leads from the meter.
3. Open the battery door by loosening the screw using a
Phillips head screwdriver.
4. Insert the battery into battery holder, observing the
correct polarity.
5. Put the battery door back in place. Secure with the two
screws.
6. Dispose of the old battery properly.
WARNING: To avoid electric shock, do not operate
your meter until the battery door is in place and
fastened securely.
1065DGMAN_20250-53-54 Manual.indd 19 8/16/2017 10:42:06 AM
19
It is recommended that Digi-Sense products are calibrated
annually to ensure proper function and accurate measure-
ments; however, your quality system or regulatory body
may require more frequent calibrations.
To schedule your recalibration, please contact InnoCal,
an ISO 17025 calibration laboratory accredited by A2LA.
Phone: 1-866-INNOCAL (1-866-466-6225)
Fax: 1-847-327-2993
E-mail: sales@innocalsolutions.com
Web: InnoCalSolutions.com
For Product and Ordering Information, Contact:
Toll-Free: 1-800-323-4340
Phone: 1-847-549-7600
Fax: 1-847-247-2929
ColeParmer.com/Digi-Sense
1065DGMAN_20250-53, -54
1065DGMAN_20250-53-54 Manual.indd 20 8/16/2017 10:42:06 AM
Toll-Free: 1-800-358-5525
Phone: 1-847-327-2000
Fax: 1-847-327-2700
Davis.com/Digi-Sense
Manual Part No. 00101-87
20
Loading...