Hellermann Tyton T820 User manual

T820
DIGITAL MULTIMETER
OPERATION MANUAL
Instruments

1. General
The instrument is a pocket digital
multimeter, which is used to measure DCV,
ACV, and DCA, resistance, diode and
continuity test. It is an ideal tool for labs,
household and wireless enthusiasts.
2. Safety Notes
1. Do not input a limit value over the range
when measuring.
2. When measuring voltage higher than
36V DCV, 25V ACV, check the
connection and insulation of the test
leads to avoid electric shock.
3. Keep the test leads away from the testing
point when converting function and range.
4. Don’t add voltage to the input terminal
when measuring resistance.
3. Specification
1. General Features

1-1. Displaying: 22mm digit height LCD
display.
1-2. Max. Indication: 1999 (31/2) auto
polarity indication.
1-3. Sampling rate: approx. 3 times/ sec
1-4. Over Range Indication: MSD displays
"1"
1-5. Low Battery Indication: " "
symbol displays.
1-6. Operation Environment: (0～40)℃,
relative humidity ＜80% .
1-7. Power: 9V battery (NEDA1604/6F22
or equivalent)
1-8. Measurement: 145×85×30mm
(Length×Width×Height)
1-9. Weight: Approx. 170g (including a 9V
battery)
1-10. Accessories: Operation Manual,
Product Certificate, Packing box, Test leads

and a 9V battery.
2. Technical Features
Accuracy: ± (a%×reading+d)
Surrounding: (23±5)℃, relative humidity
＜75%. One year warranty since the date of
manufacture.
2.1 DCV
Range
Accuracy
Resolution
200mV
±
(0.5%+4)
100uV
2V
1mV
20V
10mV
200V
100mV
600V
±
(1.0%+5)
1V
Input impedance: 1MΩfor all ranges.
2.2 ACV
Range
Accuracy
Resolution
200V
±
100mV

600V
(1.2%+10)
1V
Input impedance: 1MΩ.
Frequency Response: (40～200)Hz
2.3 DCA
Range
Accuracy
Resolution
20uA
±
(1.5%+3)
0.01uA
200uA
0.1uA
2mA
1uA
20mA
10uA
200mA
100uA
10A
±
(2.0%+5)
10mA
Max. Input current: 10A (no more than 6
seconds)
Overload Protection: 0.2A/250V;
10A/250V fuse.
2.4 Resistance

Overload Protection: 250V DC/AC peak
value
Note: At range 200Ω, first short-circuit the
meter pens to measure the wire
Range
Accuracy
Resolution
200Ω
±
(0.8%+5)
0.1Ω
2kΩ
±
(0.8%+3)
1Ω
20kΩ
10Ω
200k
Ω
100Ω
20M
Ω
±
(1.0%+15)
10kΩ

resistance. Then subtract it from the
real measurement.
2.5 Diode and continuity test
Range
Display
Testing
Condition
Forward
voltage drop of
diode
Forward
DCA is
approx.
1mA，
Backward
voltage is
apporx.3V
Buzzer makes
a long sound
while
resistance is
less than (70±
20)Ω
Open
voltage is
approx.3V
Overload Protection: 250V DC/AC

peak value
2.6 DC Voltage Measurement
1. Apply the black test lead to "COM"
terminal and the red test lead to “V/Ω”
terminal.
2. Set the knob to a proper DCV range, and
connect the test leads crossly to the
electric circuit under test. LCD displays
polarity and voltage under test connected
by the red test lead.
Note:
1. Firstly, the knob should be set to the
highest range if users have no idea about
the range of voltage under test. Then
select the proper range based on display
value.
2. If MSD displays “1", it means the meter
is over range. Please set the knob to a
higher range.

3. Do not attempt to input voltage over
600V. Otherwise, it may damage the circuit
of the meter.
4. Avoid touching high voltage circuit
when measuring it.
2.7 AC Voltage Measurement
1. Apply the black test lead to "COM"
terminal and the red test lead to “V/Ω”
terminal.
2. Set the knob to a proper ACV range, and
connect the test leads crossly to the electric
circuit under test.
Note:
1. Firstly, the knob should be set to the
highest range if users have no idea about
the range of voltage under test. Then
select the proper range based on display
value.
2. If MSD displays “1", it means the meter

is over range. Please set the knob to a
higher range.
3. Do not attempt to input voltage over
600Vrms. Otherwise, it may damage the
circuit of the meter.
4. Avoid touching high voltage circuit
when measuring it.
2.8 DC Current Measurement
1. Apply the black test lead to "COM"
terminal and the red test lead to “V/Ω”
terminal (max. 200mA), or put the red
test lead to "10A" terminal (max. 10A).
2. Set the knob to a proper DCA range, and
connect the test leads in series to the
electric circuit under test. LCD displays
polarity and current value under test
connected by the red test lead.
Note:
1. Firstly, the knob should be set to the

highest range if users have no idea about
the range of voltage under test. Then
select the proper range based on display
value.
2. If MSD displays “1", it means the meter
is over range. Please set the knob to a
higher range.
3. The max input current is 200mA or 10A
(depends on the insert position of the red
meter pen). Excessive current will melt
the fuse. When measuring, if the meter
has no reading display, please check
relevant fuse.
2.9 Resistance Measurement
1. Apply the black test lead to "COM"
terminal and the red test lead to “V/Ω”
terminal.
2. Set the knob to a proper resistance range,
and connect the leads crossly to the

resistance under test.
Note:
1. The LCD displays "1" when the
resistance is over the selected range. The
knob should be adjusted to a higher
range. When resistance under test is over
1MΩ, the reading shall be stable in a few
seconds, which is a normal status when
measuring high resistance.
2. When the input terminal is in open
circuit, it displays overload.
3. When measuring in line resistor, be sure
that the power is off and all capacitors are
released completely.
4. It is absolutely forbidden to input
voltage at the range of resistance, though
the meter has voltage protection function
at this range.
2.10 Diode Test

1. Apply the black test lead to "COM"
terminal and the red lead to "V/Ω" terminal
(the polarity of red lead is “+”)
2. Set the knob to“”range, connect test
leads to the diode under test. The red test
lead connects to diode positive polarity
and the reading is the approx. value of
diode forward voltage drop.
2.11 Continuity Test
Set the knob to“”range, apply test leads
to the two points of tested circuit. If the
inner buzzer sounds, the resistance is less
than (70±20) Ω.
4. Maintenance
This is a precise meter; please don't try to
modify the circuit.
Note:
1. Do not input voltage over DC600V or
AC 600Vrms.

2. Do not measure voltage on range Ω.
3. Do not use this meter for measurement if
the battery is not correctly placed or the
back case is not properly screwed.
4. Remove the test leads from the testing
points and turn off the meter before
replacing battery or fuse.
Battery Replacement
Note: Pay attention to the battery status.
Please replace the battery when LCD
displays “”.
Steps:
1. Unscrew the battery cover.
2. Take out the 9V battery and replace it
with a new one.
3. Install and screw the battery cover.
Fuse Replacement (This operation could
only be processed in power off status.)
1. Unscrew the battery cover.

2. Take out the battery and open the back
cover.
3. Please use fuse of the same specification.
The operation manual is subject to
change without notice.
The content of this manual is regarded
as correct. In case readers find any
errors and missing parts, please contact
the manufacturer.
The Company shall not be held liable for
any accidents and hazards resulted from
the mal-operations by the user.
The function stated in this operation
manual can not be taken as the reason
for using the product for special
purposes.

This product needs to connect high
voltage for measurement, so please don't
try to modify the circuit. Users who
modify the circuit by themselves should
take the responsibility of any
consequence caused.
601E-830L-000C