UNI-T UT70C Operating Manual

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Table of Contents

Title

Overview Unpacking Inspection Safety Information Rules For Safe Operation International Electrical Symbols The Meter Structure Rotary Switch Functional Buttons Display Symbols Measurement Ranges

A. Selecting a Measurement Range B. Manual Ranging and Autoranging

Measurement Operation

A. AC Voltage Measurement B. DC Voltage Measurement C. DC Milivolt Measurement D. Measuring Continuity, Resistance,

Conductance & Capacitance E. Testing Diodes F. DC or AC Current Measurement G. Frequency & Duty Cycle Measurement

MAX MIN Recording Mode PEAK MAX MIN Mode Operation of Hold Mode Operation of Auto Hold Mode The Use of Relative Value and Relative Percentage Value Mode Turning on the Display Backlight Analogue Bar Graph Display Full Icons Display Sleep Mode General Specifications

Model UT70C: OPERATING MANUAL

Page

37 37 37

38 38 38 39 39 40 41 41 42 43 44 45 45 45

Accuracy Specifications

A. AC Voltage B. DC Voltage C. Continuity, Resistance & Conductance Test D. Capacitance

Diodes Test

DC Current

AC Current

H. Frequency & Duty Cycle

Maintenance

A. General Service B. Testing the Fuses C. Replacing the Battery D. Replacing the Fuses

RS232C Serial Port

A. RS232C Port Cable B. Setting of RS232C Serial Ports C. System Requirements for Installing the

UT70C Interface Program

Model UT70C: OPERATING MANUAL

Overview

This Operating Manual covers information on safety and cautions. Please read the relevant information carefully and observe all the Warnings and Notes strictly.

Warning To avoid electric shock or personal injury, read the "Safety Information" and "Rules for Safe Operation" carefully before using the Meter.

Your multimeter is an intelligent digital one, a precise instrument with a resolution of 8,000 counts and up-todate automatic computer calibrating function. High resolution A/D converter and micro-controller data processing technique is adopted in the Meter, featured with intelligence, high precision and multi-functions. The Meter can be widely used in laboratory, field service, domestic and other applications. All the functions and ranges have overloaded protection.

Model UT70C: OPERATING MANUAL

Unpacking Inspection

Open the package case and take out the Meter. Check the following items carefully to see any missing or damaged part:

In the event you find any missing or damage, please contact your dealer immediately.

Item

1 2 3 4

5 6

7 8

Description

Operating Manual Test Lead Test Clip 9V Battery (NEDA1604, 6F22 or 006P) (installed) RS232C Interface Cable CD-ROM (Installation Guide & Computer Interface Software) Holster Tilt Stand

Qty

1 piece

1 pair 1 pair

1 piece 1 piece

1 piece

Model UT70C: OPERATING MANUAL

Safety Information

CA T. II: Local level, appliance, PORTABLE EQUIPMENT etc., with smaller transient voltage overvoltages than CAT. III

CA T. III: Distribution level, fixed installation, with smaller transient overvoltages than CAT. IV

CAT IV: Primary supply level, overhead lines, cablesystems etc.

Use the Meter only as specified in this operating manual, otherwise the protection provided by the Meter may be impaired.

In this manual, a Warning identifies conditions and actions that pose hazards to the user, or may damage the Meter or the equipment under test.

A Note identifies the information that user should pay attention on.

International electrical symbols used on the Meter and in this Operating Manual are explained on page 8.

Model UT70C: OPERATING MANUAL

CE Version: The Meter complies with the standards IEC61010-1:in pollution degree 2, overvoltage category CAT III 1000V, CAT IV 600V and double insulation . UL V ersion: The Meter complies with the standards UL61010B-1, in pollution degree 2, overvoltage category CAT II 1000V and double insulation.

Rules For Safe Operation (1)

Warning To avoid possible electric shock or personal injury, and to avoid possible damage to the Meter or to the equipment under test, adhere to the following rules:

l Before using the Meter inspect the case. Do

not use the Meter if it is damaged or the case

(or part of the case) is removed. Look for cracks

or missing plastic. Pay attention to the insulation

around the connectors. l Inspect the test leads for damaged insulation

or exposed metal. Check the test leads for

continuity. Replace damaged test leads with

identical model number or electrical

specifications before using the Meter. l Do not apply more than the rated voltage, as

marked on the Meter, between the terminals or

between any terminal and grounding. l The rotary switch should be placed in the right

position and no any changeover of range shall

be made during measurement is conducted to

prevent damage of the Meter. l Never working at an effective voltage over 60V

in DC or 30V rms in AC for there is danger of

electric shock. l Use the proper terminals, function, and range

for your measurements. l Do not use or store the Meter in an environment

of high temperature, humidity, explosive,

inflammable and strong magnetic field. The

performance of the Meter may deteriorate after

dampened. l When using the test leads, keep your fingers

behind the finger guards.

Model UT70C: OPERATING MANUAL

Rules For Safe Operation (2)

l Disconnect circuit power and discharge all high-

voltage capacitors before testing resistance,

conductance, continuity, diodes, current, or

capacitance. l Before measuring current, check the Meter's

fuses and turn off power to the circuit before

connecting the Meter to the circuit. l Replace the battery as soon as the battery

indicator

appears. With a low battery, the Meter might produce false readings that can lead to electric shock and personal injury.

l Remove test leads, RS232C interface cable and

test clip from the Meter and turn the Meter power off before opening the Meter case.

l When servicing the Meter, use only the same

model number or identical electrical specifications replacement parts.

l The internal circuit of the Meter shall not be

altered at will to avoid damage of the Meter and any accident.

l Soft cloth and mild detergent should be used

to clean the surface of the Meter when servicing. No abrasive and solvent should be used to prevent the surface of the Meter from corrosion, damage and accident.

l The Meter is suitable for indoor use. l Turn off the Meter when it is not in use and

take out the battery when not using for a long time.

l Constantly check the battery as it may leak when

it has been using for some time, replace the battery as soon as leaking appears. A leaking battery will damage the Meter.

Model UT70C: OPERATING MANUAL

International Electrical Symbols

The Meter Structure (see figure 1)

(figure 1)

1 Front Case 2 LCD Display 3 Functional Buttons 4 Rotary Switch 5 Input Terminals

AC (Alternating Current) DC (Direct Current) AC or DC Grounding Double Insulated Deficiency of Built-In Battery Continuity Test Diode Capacitance Test Fuse Warning. Refer to the Operating Manual Conforms to Standards of European Union

Model UT70C: OPERATING MANUAL

OFF

Rotary Switch

Below table indicated for information about the rotary switch positions.

Rotary Switch

Position

Function

Power is turned off. AC voltage measurement.

DC voltage measurement. DC millivolt measurement.

: Continuity test. : Resistance measurement. : Capacitance test.

Diode Test. AC or DC Current Measurement

from 0.001A to 10.00A . AC or DC Current Measurement from 0.1mA to 800.0mA.

Model UT70C: OPERATING MANUAL

Functional Buttons (1)

Below table indicated for information about the functional button operations.

Button Operation PerformedMeasuring

Function

Continuity Test

Turn the continuity buzzer on and off in resistance measurement mode.

At OFF position

At REC mode or REC mode plus Hold mode

Press while turning on the Meter to disable the beeper at all functions except short circuit and diode testing.

To toggle between 100ms response time and 1ms response time under REC mode except at resistance, capacitance and continuity range.

MAX

MIN

Any rotary switch position except at conductance mode.

Starts recording of maximum and minimum values. Steps the display through the sequence of present, high (MAX), low (MIN) and average (AVG) readings at any mode. In 1ms response time, it steps through only MAX and MIN reading.

At OFF position

To select 1 second high accuracy response time, press and hold down MAX MIN while turning the rotary switch to any function setting.

RANGEAny rotary

switch position

1. Press RANGE to enter the manual ranging mode; the Meter beeps.

2. Press RANGE to step through the ranges available for the selected function; the Meter beeps.

3. Press and hold RANGE for over 1 second to return to autoranging; the Meter beeps.

Model UT70C: OPERATING MANUAL

HOLD Any rotary

switch position

Press HOLD to enter and exit the Hold mode in any mode; the Meter beeps.

Functional Buttons (2)

Conductance mode

Press HOLD to toggle between conductance and resistance value. Present resistance value is kept.

Press to select capacitance test.

A , mA Press to select DC or AC

current. DC is default.

At OFF position

To disable the Sleep Mode, press

while turning on the Meter.

REL

Any rotary switch position

Press REL to enter and exit the

and

% mode in any measuring

mode; the Meter beeps.

Hz V , V ,

, A ,

1. Press Hz to enter frequency measurement mode; the Meter beeps.

2. Press Hz again to enter duty cycle measurement mode; the Meter beeps.

3. Press Hz again to return to the last measurement mode; the Meter beeps.

Display Backlight

Press once to turn the Display Backlight on and it shall shut off automatically in around 60 seconds later.

Model UT70C: OPERATING MANUAL

No. MeaningSymbol

Display Symbols (1) (see figure 2)

(figure 2)

The Meter is in the auto range mode in which the Meter automatically selects the range with the best resolution.

The battery is low.

Warning: To avoid false readings, which could lead to possible electric shock or personal injury, replace the battery as soon as the battery indicator appears.

Indicates negative reading.

Test of diode.

The continuity buzzer is on.

The relative value mode is on, which display the present value minus the stored value.

The relative percentage value mode is on. It displays the percentage value of the relative value and stored value.

DATA

HOLD

Data hold is active.

DC AC Indicator for DC/AC voltage or current.

The displayed value is the mean value.

Display the present chosen range.8000mV

Percent, used for duty cycle measurements.

Model UT70C: OPERATING MANUAL

V, mV

Display Symbols (2)

k , M

W: Ohm. The unit of resistance. kW: kilohm. 1 x 103 or 1000 ohms. MW: Megohm. 1 x 106 or 1,000,000

ohms.

Hz, kHz,

MHz

Hz: Hertz. The unit of frequency. kHz: Kilohertz. 1 x 103 or 1000 hertz. MHz: Meghertz. 1 x 106 or1,000,000

hertz.

V: Volts. The unit of voltage. mV: Millivolt. 1 x 10-3 or 0.001 volts.

A: Amperes (amps). The unit of

current.

mA: Milliamp. 1 x 10-3 or 0.001

amperes.

F: Farad. The unit of capacitance. mF: Microfarad. 1 x 10

-6

or 0.000001

farads.

nF: Nanofarad. 1 x 10-9 or

0.000000001 farads.

S: Siemens. The unit of

conductance.

nS: Nanosiemens. 1 x 10-9 or

0.000000001 siemens.

Maximum, minimum and average recording mode enabled. Present reading displayed.

100ms response time. Maximum reading displayed. Minimum reading displayed. Average reading displayed.

Provides an analogue indication of the present input, quick response.

Polarity indicator for the analogue bar graph display, no display for positive.

The input value is too large for the selected range.

Computer and the Meter is connected properly. Data output is in progress.

A, mA

F , F, nF

100ms

MAX

MIN

AVG

Analogue

Bar

Graph

RS232C

K : M :

Model UT70C: OPERATING MANUAL

Measurement Ranges (1)

A measurement range determines the highest value the Meter can measure. Most Meter functions have more than one range. See "Accuracy Specifications."

A. Selecting a Measurement Range

Being in the right measurement range is important: l If the range is too low for the input, the Meter displays

to indicate an overload.

l If the range is too high, the Meter will not display

the most accurate measurement.

B. Manual Ranging and Autoranging

The Meter has both manual range and autorange options: l In the autorange mode, the Meter selects the best

range for the input detected. This allows you to switch test points without having to reset the range.

l In the manual range mode, you select the range.

This allows you to override autorange and lock the Meter in a specific range.

The Meter defaults to the autorange mode in measurement functions that have more than one range. When the Meter is in the autorange mode, is displayed.

To enter and exit the manual range mode:

Model UT70C: OPERATING MANUAL

1. Press RANGE. The Meter enters the manual range mode and turns off. Each presses of RANGE increments the range. When the highest range is reached, the Meter wraps to the lowest range.

2. To exit the manual range mode, press and hold RANGE for over one second. The Meter returns to the autorange mode and is displayed.

Note

l In Hold and MAX MIN mode, press RANGE exits

these measurement modes and enters manual range mode.

l In Hz measurement mode, press RANGE to attenuate

10 times of input signal amplitude which can increase the Meter sensitivity and stabilize the correct reading.

Measurement Ranges (2)

Model UT70C: OPERATING MANUAL

Measurement Operation (1)

A. AC Voltage Measurement (see figure 3)

Warning T o avoid harms to you or damages to the Meter from electric shock, please do not attempt to measure voltages higher than 1000V / 750V rms although readings may be obtained.

The AC Voltage ranges are: 800.0mV, 8.000V, 80.00V,

800.0V and 1000V. To measure AC Voltage, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to V

3. Connect the test leads across with the object being

measured. The measured value shows on the display, which is effective value of sine wave (mean value response).

Note

l In each range, the Meter has an input impedance

of 10M . This loading effect can cause measurement errors in high impedance circuits. If the circuit impedance is less than or equal to 10k , the error is negligible (0.1% or less).

l When AC voltage measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

(figure 3)

blackred

Model UT70C: OPERATING MANUAL

(figure 4)

B. DC Voltage Measurement (see figure 4)

Measurement Operation (2)

Warning T o avoid harms to you or damages to the Meter from electric shock, please do not attempt to measure voltages higher than 1000V / 750V rms although readings may be obtained.

The DC Voltage ranges are: 8.000V, 80.00V, 800.0V and 1000V. To measure DC Voltage, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to V

3. Connect the test leads across with the object being

measured. The measured value shows on the display.

Note

l In each range, the Meter has an input impedance

of 10M . This loading effect can cause measurement errors in high impedance circuits. If the circuit impedance is less than or equal to 10k , the error is negligible (0.1% or less).

l When DC voltage measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

blackred

Model UT70C: OPERATING MANUAL

(figure 5)

Measurement Operation (3)

C. DC Millivolt Measurement (see figure 5)

Warning T o avoid harms to you or damages to the Meter from electric shock, please do not attempt to measure voltages higher than 1000V / 750V rms although readings may be obtained.

The DC Millivolt ranges are: 80.00mV and 800.0mV. These ranges have more than 4000M . To measure DC Millivolt, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to mV

3. Connect the test leads across with the object being

measured. The measured value shows on the display.

Note

l In each range, the Meter has an input impedance

of 10M . This loading effect can cause measurement errors in high impedance circuits. If the circuit impedance is less than or equal to 10k , the error is negligible (0.1% or less).

l When DC millivolt measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

blackred

Model UT70C: OPERATING MANUAL

(figure 6)

Measurement Operation (4)

D. Measuring Continuity, Resistance,

Conductance & Capacitance

Warning To avoid damages to the Meter or to the devices under test, disconnect circuit power and discharge all the high-voltage capacitors before measuring continuity , resistance, conductance and capacitance.

When measuring capacitance, use the DC Voltage function to confirm that the capacitor is discharged. Never attempt to input over 60V in DC or 30V rms in AC to avoid personal dangerous.

Testing for Continuity (see figure 6)

To test for continuity, connect the Meter as below:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to

and press to

select

measurement mode.

3. The buzzer sounds if the resistance of a circuit under

test is less than 100 .

Note

l The LCD displays

indicating the circuit being

tested is open.

l When continuity testing has been completed,

disconnect the connection between the testing leads and the circuit under test.

Select

Test

blackred

Model UT70C: OPERATING MANUAL

(figure 7)

Resistance Measurement (see figure 7)

Measurement Operation (5)

The resistance ranges are: 800.0 , 8.000k , 80.00k ,

800.0k , 8.000M and 80.00M . To measure resistance, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to

, resistance

measurement is default or press

to select

measurement mode.

3. Connect the test leads across with the object being

measured. The measured value shows on the display.

Note

l The test leads can add 0.1 to 0.2 of error to

resistance measurement. To obtain precision readings in low-resistance measurement, that is the range of 800.0 , short-circuit the input terminals beforehand, using the relative value function button

REL

to automatically subtract the value measured when the testing leads are short-circuited from the reading.

l For high-resistance measurement (>1M ), it is normal

taking several seconds to obtain a stable reading.

Select W Test

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Model UT70C: OPERATING MANUAL

Measurement Operation (6)

l The LCD displays

indicating open-circuit for the tested resistor or the resistor value is higher than the maximum range of the Meter.

l When resistance measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Conductance Measurement (see figure 8)

(figure 8)

Select nS Test

blackred

The resistance ranges from 0.01nS to 80nS. To measure conductance, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to

and press RANGE

to select nS measurement mode.

3. Connect the test leads across with the object being measured. The measured value shows on the display.

Note

l It is possible to press HOLD to toggle between

conductance and resistance value during the measurement of conductance.

l When conductance measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Model UT70C: OPERATING MANUAL

(figure 9)

Measurement Operation (7)

Capacitance Measurement (see figure 9)

The Meter's capacitance ranges are: 1.000nF, 10.00nF,

100.0nF, 1.000

F, 10.00 F and 100.0 F. To measure

capacitance, connect the Meter as follows:

1. Insert the red test lead or the red test clip into the

V Hz terminal and the black test lead or black

test clip into the COM terminal.

2. Set the rotary switch to

and press to

select nF measurement mode.

3. Connect the test leads or the test clips across with the object being measured. The measured value shows on the display.

Note

l For testing the capacitor with polarity, connect the

red test clip or red test lead to anode & black test clip or black test lead to cathode instead.

l It takes a longer time when testing a high capacitor

value, the testing time is around 15 seconds in 100

F range.

l When capacitance measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Select nF Test

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Model UT70C: OPERATING MANUAL

Measurement Operation (8)

E. Testing Diodes (see figure 10)

(figure 10)

Warning To avoid possible damage to the Meter and to the device under test, disconnect circuit power and discharge all high-voltage capacitors before testing diodes.

Use the diode test to check diodes, transistors, and other semiconductor devices. The diode test sends a current through the semiconductor junction, then measures the voltage drop across the junction. A good silicon junction drops between 0.5V and 0.8V.

To test a diode out of a circuit, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to

3. For forward voltage drop readings on any

semiconductor component, place the red test lead on the component's anode and place the black test lead on the component's cathode. The measured value shows on the display.

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Model UT70C: OPERATING MANUAL

(figure 11)

Measurement Operation (9)

Note

l In a circuit, a good diode should still produce a

forward voltage drop reading of 0.5V to 0.8V; however, the reverse voltage drop reading can vary depending on the resistance of other pathways between the probe tips.

l Connect the test leads to the proper terminals as

said above to avoid error display.

l The LCD will display

indicating open-circuit for

wrong connection.

l The unit of diode is Volt (V), displaying the positive-

connection voltage-drop value.

l When diode testing has been completed, disconnect

the connection between the testing leads and the circuit under test.

F. DC or AC Current Measurement (see figure 11)

Warning Never attempt an in-circuit current measurement where the open-circuit voltage between the circuit and ground is greater than 250V. If the fuse burns out during measurement, the Meter may be damaged or the operator himself may be hurt. Use proper terminals, function, and range for the measurement. When the testing leads are connected to the current terminals, do not parallel them across any circuit.

Select AC or DC Test

black red

A or mA

Model UT70C: OPERATING MANUAL

Measurement Operation (10)

The current measurement has 2 measurement positions on the rotary switch: A

and mA .

The A has a 8.000A and 10.00A range, with auto ranging; the mA has a 80.00mA and 800.0mA range, with auto ranging.

To measure current, do the following:

1. Turn off power to the circuit. Discharge all high-

voltage capacitors.

2. Insert the red test lead into the A or mA or terminal

and the black test lead into the COM terminal.

3. Set the rotary switch to A

or mA .

Use the A terminal and A

measurement position

if the current value to be tested is an unknown.

4. The Meter defaults to DC current measurement

mode. To toggle between DC and AC current measurement function, press

. AC current is displayed as an mean value (calibrated against sine wave effective value).

5. Break the current path to be tested. Connect the red test lead to the more positive side of the break and the black test lead to the more negative side of the break.

6. Turn on power to the circuit. The measured value shows on the display.

Note

l For safety sake, the measuring time for high current,

that is 8.000A and 10.00A range, should be

10 seconds for each measurement and the interval time between 2 measurements should be greater than 15 minutes.

l When current measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Model UT70C: OPERATING MANUAL

(figure 12)

Measurement Operation (11)

G. Frequency & Duty Cycle Measurement (see figure 12)

Frequency Measurement

The measurement ranges are: 1kHz, 10kHz, 100kHz and 1MHz. The maximum measurement range is 1MHz. To measure frequency, connect the Meter as follows:

1. Insert the red test lead into the

V Hz terminal

and the black test lead into the COM terminal.

2. Set the rotary switch to any voltage or current measurement positions.

3. Press Hz to display the frequency of present signal.

4. Connect the test leads across with the object being measured. The measured value shows on the display.

Note

l It is recommended to use mV

range which has

the highest sensitivity.

l The attenuate amplitude of signal is different from

different measuring positions and ranges, therefore the required input amplitude is different when measuring frequency at different measuring positions and ranges.

l When Hz measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Select Hz

or Duty Cycle

Test

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Model UT70C: OPERATING MANUAL

Measurement Operation (12)

Duty Cycle Measurement

The duty cycle measurement range is 0.01% ~ 99.99%. To measure duty cycle:

1. Set up the Meter to measure frequency.

2. To select duty cycle, press Hz again (or until the % symbol is shown on the display).

3. Connect the test leads across with the object being measured. The measured value shows on the display.

Note

l It is recommended to use mV

range.

l The polarity of trigger slope is positive. l The attenuate amplitude of signal is different from

different measuring positions and ranges, therefore the required input amplitude is different when measuring duty cycle at different measuring positions and ranges.

l When duty cycle measurement has been completed,

disconnect the connection between the testing leads and the circuit under test.

Model UT70C: OPERATING MANUAL

MAX MIN recording mode applies to all measurement functions except at conductance measurement function.

MAX MIN recording mode captures and stores the maximum and minimum input value detected, and calculates a running average of all readings taken.

In the MAX MIN mode, when the Meter detects an input that is below the recorded minimum or above the recorded maximum, the Meter beeps and records the new minimum (MIN) or maximum (MAX) value.

In the MAX MIN mode, you can also display a running average of all readings taken since the MAX MIN mode was activated. Displaying the average reading allows you to "smooth" a rapidly changing input by displaying a stable reading on the digital display.

The MAX MIN mode has a pre-set response time of 100ms. A shorter response time captures shorter events, but with decreased accuracy. If you want 1 second response time, that can be selected after power on the Meter.

To use the MAX MIN mode as follows:

(figure 13)

MAX MIN Recording Mode (1) (see figure 13)

Select MAX, MIN, AVG or

Present value

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Model UT70C: OPERATING MANUAL

MAX MIN Recording Mode (2)

To select response time

l The pre-set response time is 100ms. l Press

to select 1 ms response time in REC mode. It is called under PEAK MAX MIN mode. (In 1 ms response time, it steps through on the sequence of MAX and MIN readings only.)

l With the rotary switch in the OFF

position, press and hold down MAX MIN while turning on the rotary switch to select 1 second high accuracy response time. (MAX MIN readings for the frequency counter are recorded only in the 1 second, high accuracy response mode.)

To exit the MAX MIN mode.

Press MAX MIN for over 1 second. The Meter exists MAX MIN. Recorded values are erased and the Meter stays in the selected range.

MAX MIN Function

Action

To enter the MAX MIN mode.

1. Make sure that the Meter is in the desired measurement function and range.

2. Press MAX MIN to enter MAX MIN recording mode. The present reading is displayed, and the Meter is locked in the present range, and

REC is displayed.

3. Each time a new low or high value is recorded, the Meter beeps and displays a new reading.

(In MAX MIN mode, Sleep Mode function will be disabled.)

To view the

MAX, MIN, A VG or present

reading.

Press MAX MIN to step through on the sequence of present readings, high (MAX), low (MIN) and average (AVG) readings.

To stop and resume recording without erasing stored values

l Press HOLD to stop recording, the

recorded values will not erase.

l Press HOLD again to resume

recording.

Model UT70C: OPERATING MANUAL

PEAK MAX MIN Mode (see figure 14)

(figure 14)

PEAK MAX MIN mode is an additional function of . Pressing

to toggle between 100ms response time and 1ms response time. This function can only be enabled when the Meter is under REC mode or REC mode plus Hold mode except at

mode.

To enter PEAK MAX MIN mode: l Press MAX MIN or MAX MIN and HOLD to enter

REC mode.

l Then press

to enter PEAK MAX MIN mode (1ms response time), it steps through the sequence of MAX and MIN reading ONLY.

Select 1ms

response time

black

red

Select MAX

or MIN

Model UT70C: OPERATING MANUAL

Operation of Hold Mode

Warning To avoid possibility of electric shock, do not use Hold mode to determine if circuits are without power. The Hold mode will not capture unstable or noisy readings.

The Hold mode is applicable to all measurement functions. With the Auto Hold function, it automatically holds the present reading on the display , freeing you to concentrate on the placement of the test leads when working in dangerous or difficult situations.

l Press HOLD to enter Hold mode; the Meter beeps. l Press HOLD again or RANGE or turn the rotary

switch to exit Hold mode; the Meter beeps.

l In Hold mode, DATA HOLD is displayed on the

LCD.

l In conductance measurement mode, press HOLD

to toggle between resistance and conductance value. Present resistance value is kept.

l The Meter displays

when the selected range is

overloaded.

l The Meter beeps when a positive result is obtained

from continuity test, whether it is under the Hold mode or not.

l If you are in MAX MIN recording mode or mode

when HOLD is selected, Hold interrupts the function. The display does not update, but recorded readings are not erased. Press HOLD again to resume recording.

Model UT70C: OPERATING MANUAL

Operation of Auto Hold Mode

Auto Hold means you no need to press HOLD, the readings on the LCD will be hold automatically.

Conditions to enter Auto Hold Mode: l When input signal is larger than AC/DC 100mV,

Auto Hold mode will be enabled automatically.

l When the change of signal three times continuously

within

3 digits, it will hold the last value; the Meter

beeps.

l Considers every value as the base value. When

the Meter detects an input which is above the base value

300 digits, the Meter beeps, and holds and

displays the value as the new base value.

Model UT70C: OPERATING MANUAL

The Use of Relative Value and Relative Percentage Value Mode

The and % mode applies to all measurement functions, with auto ranging. REL mode can be used together with Auto Hold and MAX MIN mode.

The definition is as follows: l Relative value (

) = present value - stored value For instance, if the stored value is 20.0V and the present value is 22.0V, the reading would be 2.0V. If a new measurement value is equal to the stored value then display 0.0V.

l Relative percentage value (

%) =

(relative value

stored value) X 100%

To enter or exit and % mode: l Use rotary switch to select the desired measurement

function before selecting REL . If measurement functions change manually after REL is selected, the Meter exits the REL mode.

l Press REL to enter mode, and the present

measurement range is locked and display the last measurement value as "0" as the stored value. Then if carrying out measurement at this time, the LCD will display the value as the result.

l Press REL again to enter % mode, and the

present measurement range is locked and display the last measurement value as "0" as the stored value. Then if carrying out measurement at this time, the LCD will display the % value as the result.

l Press REL again or turn the rotary switch to reset

the stored value and exit % and mode, returning to normal measurement mode.

Model UT70C: OPERATING MANUAL

Turning on the Display Backlight

Warning In order to avoid the hazard arising from mistaken readings in insufficient light or poor vision, please use the Display Backlight function.

l Press

to turn on the Display Backlight and it will

automatically off after about 60 seconds.

l Press and hold

for about 2 seconds to turn the

Display Backlight off.

Analogue Bar Graph Display

The analogue bar graph likes the needle in a traditional analogue meter (AMM). It refreshes 50 times a sec, which is 10 times faster than that of digital display and is applied to zero adjustment and observation of rapidly changing signal that make digital display hard to read.

The analogue display is divided uniformly into 10 scales and composed of 41 segments; of which the full-range value corresponds to the full-range value of the measurement range that has been selected. The polarity of the measured value is displayed as "-" on the left of the analogue display: positive polarity is not displayed. For example, when 80V range is selected, the full-range value of the analogue display is 80V, and as the full range is uniformly divided into 10 grades, each grade denotes 8V; If the input is 40V, the high-lighted bar-shape will be at the position indicated by the number 5. if the input is -40V, a "-" sign will appear on the left of the analogue display.

There is no analogue displaying value when making measurement of frequency, diode, conductance and capacitance.

Model UT70C: OPERATING MANUAL

Full Icons Display

If the Meter is turned on with any functional button being pressed on, the LCD will display all the icons and maintain this mode until the button is released 3 seconds later.

Sleep Mode

l To preserve battery life, the Meter automatically

turns off if you do not turn the rotary switch or press any button for about 30 minutes. The buzzer beeps three times 5 minutes before turning off.

l The Meter can be activated by turning the rotary

switch or pressing any button. If the Meter is activated by turning the rotary switch, it will start from the switch selected function.

l To disable the Sleep Mode, press

while turning

on the Meter.

l In MAX MIN mode, the Sleep Mode is disabled.

Model UT70C: OPERATING MANUAL

l Maximum Display l Temperature

l Relative Humidity l Altitude l Battery Type

l Battery Deficiency l Data Holding l Negative reading l Overloading l Equipped with full icons display. l Auto and manual range selectable. l Dimensions (HxWxL) l Weight

l Safety/Compliances

l Maximum Voltage between

any Terminals and Grounding

:1000V rms.

:1A,250V fast type glass

fuse, 5x20mm.

:8000, updates 5 times

/second.

:Operating:5oC~40oC

(41oF ~104oF).

Storage:-10oC~50oC

(14oF~122oF). :<80% @ 5oC - 31oC; <50% @ 31oC - 40oC. :Operating: 2000 m. Storage: 10000 m. :One piece of 9V

NEDA1604 or 6F22 or 006P.

:Display

. :Display DATA HOLD. :Display . :Display

:195 x 90 x 39 mm. :Approximate 550g (battery

included).

General Specifications

:10A,250V fast type glass fuse, 5x20mm.

CE Version: IEC61010 CAT III 1000V, CAT IV 600V overvoltage and double insulation standard.

UL Version:UL 61010B-1, CAT II 1000V overvoltage double insulation standard.

l Certification:

/UL

This meter is suitable for indoor use.

Model UT70C: OPERATING MANUAL

Accuracy Specifications (1)

Accuracy:

(a% reading + b digits), guarantee for 1 year.

Operating temperature: 23oC

5oC. Relative humidity: <80%. Temperature coefficient: 0.1 x (specified accuracy) / 1oC

A. AC Voltage

Range Resolution

Accuracy

50Hz~60Hz

(1%+3)

40Hz~400Hz

(1.5%+4) (1.5%+3) (2.5%+4)

800mV

80V

800V

1000V

100 V

1mV

10mV

100mV

Overload Protection:

AC/DC: 1000V rms

Remarks:

l Input impedance: 10M . l Displays effective value of sine wave (mean value

response).

l Frequency response 40Hz ~ 400Hz.

B. DC Voltage

Range

80mV

800mV

80V

800V

1000V

Overload Protection

AC/DC: 1000V rms

Accuracy

(0.1%+3)

(0.1%+1)

Resolution

100

1mV

10mV

100mV

Remarks: l At 80mV ~ 800mV Range:

Input impedance

4000M .

l At 8V ~ 1000V Range:

Input impedance

10M .

Model UT70C: OPERATING MANUAL

Approximate

100

(0.5%+3) (0.5%+1)

(2%+3)

(2%+10)

Accuracy Specifications (2)

C. Continuity, Resistance & Conductance Test

Continuity Test

(800.0 )

800

80k

800k

80M

Conductance Test

(80nS)

0.1

0.1 1

100

10k

0.01nS

Range Resolution Accuracy

Overload

Protection

500V rms

Remarks: l Continuity Test (800.0 ):

Buzzer beeps continuously. Open circuit voltage approximate 0.7V.

l At 800 ~ 80M Range:

Open circuit voltage approximate 0.7V.

l Conductance Test (80ns):

80nS = 12.5M .

D. Capacitance

Range Resolution Accuracy

Overload

Protection

1nF

10nF

100nF

100

1pF

10pF

100pF

1nF

10nF

100nF

(3%+5)

(2%+3)

(3%+5)

500V rms

Remark:

Reading under 1nF is only for reference.

E. Diodes Test

Range

Diode

Resolution

1mV

Overload Protection

500V rms

Remarks:

l Open circuit voltage approximate 3V. l Displays approximate forward voltage drop reading.

Model UT70C: OPERATING MANUAL

Accuracy Specifications (3)

F. DC Current

Range

Resolution

Accuracy

Overload

Protection

(0.3%+2)

80mA

800mA

10A

10 A

100 A

1mA

10mA

Remark: l At 8A & 10A Range:

For continuous measurement

10 seconds and interval time between 2 measurements greater than 15 minutes.

G. AC Current

Range Resolution Accuracy

Overload

Protection

(0.8%+2)

(1.2%+2)

80mA

800mA

10A

10 A

100 A

1mA

10mA

Remarks: l At 8A & 10A Range:

For continuous measurement

10 seconds and interval time between 2 measurements greater than 15 minutes.

l Displays effective value of sine wave (mean value

response).

l Frequency response 40Hz ~ 1kHz.

1A,250V fast type glass fuse, 5x20mm.

10A,250V fast type glass fuse, 5x20mm.

1A,250V fast type glass fuse, 5x20mm.

Model UT70C: OPERATING MANUAL

Accuracy Specifications (4)

H. Frequency & Duty Cycle

Frequency - At mV

Range

Remarks:

l Input sensitivity as follows:

<100kHz:

100mV rms;

100kHz: 500mV rms;

l Maximum input amplitude: 30V rms.

Frequency - At V

& V Range

Range Resolution Accuracy

Overload

Protection

500V rms(0.02%+1)

0.01Hz

0.1Hz 1Hz

10Hz

1kHz

10kHz

100kHz

1MHz

Range Accuracy Overload Protection

1000V(0.1%+3)10Hz~100kHz

Remarks:

l Input amplitude:

500mV rms.

l Maximum input amplitude: 30V rms.

Frequency - At A

& mA Range

Remark:

l Input amplitude:

3000 digits.

Duty Cycle

Range Accuracy Overload Protection

(0.1%+3)50Hz ~ 10kHz

Range Resolution Accuracy

Overload

Protection

500V rms(1%+5)0.01%1% ~ 99%

10A,250V fast type glass fuse, 5x20mm.

1A,250V fast type glass fuse, 5x20mm.

Model UT70C: OPERATING MANUAL

Maintenance (1)

This section provides basic maintenance information including battery and fuse replacement instruction.

Warning Do not attempt to repair or service your Meter unless you are qualified to do so and have the relevant calibration, performance test, and service information. T o avoid electrical shock or damage to the Meter, do not get water inside the case.

A. General Service

l Periodically wipe the case with a damp cloth and

mild detergent. Do not use abrasives or solvents.

l To clean the terminals with cotton bar with detergent,

as dirt or moisture in the terminals can affect readings.

l Turn the Meter to OFF position when it is not in use

and take out the battery when not using for a long time.

l Do not store the Meter in a place of humidity, high

temperature, explosive, inflammable and strong magnetic field.

Remarks:

l Reading is only for reference purpose. l At mV

8V Range:

Positive pulse width

30 s.

Accuracy Specifications (5)

Model UT70C: OPERATING MANUAL

Maintenance (2)

B. Testing the Fuses

Warning T o avoid electrical shock or personal injury, remove the test leads and any input signals before replacing the battery or fuse. T o prevent damage or injury , install ONL Y replacement fuses with identical amperage, voltage, and speed ratings.

To test the fuse:

1. Set the rotary switch to

and select by

pressing

2. Plug a test lead into the terminal

V Hz and touch

the probe tip to the 10A or mA terminal.

l If the Meter beeps, the fuse is good. l If the display shows

, replace the fuse and test

again.

l If the display shows any other value, have the

Meter serviced and contact your dealer immediately.

If the Meter does not work while the fuse is all right, send it to your dealer for repair.

Model UT70C: OPERATING MANUAL

Warning T o avoid false readings, which could lead to possible electric shock or personal injury , replace the battery as soon as the battery indicator "

" appears.

To replace the battery:

1. Turn the Meter to OFF position and remove all

connections from the terminals.

2. Take out the Meter from the holster.

3. Remove the 3 rubber feet and then 3 screws from

the case bottom, and separate the case top from the case bottom.

4. Remove the battery from the battery connector.

5. Replace the battery with a new 9V battery

(NEDA1604, 6F22 or 006P).

6. Rejoin the case bottom and case top, and reinstall

the 3 screws and 3 rubber feet.

(figure 15)

Maintenance (3)

C. Replacing the Battery (see figure 15)

The Meter

Holster

Model UT70C: OPERATING MANUAL

Maintenance (4)

D. Replacing the Fuses (see figure 15)

Warning To avoid electrical shock or arc blast, or personal injury or damage to the Meter, use specified fuses ONLY in accordance with the following procedure.

To replace the Meter's fuse:

1. Turn the Meter to OFF position and remove all

connections from the terminals.

2. Take out the Meter from the holster.

3. Remove the 3 rubber feet and 3 screws from the

case bottom, and separate the case top from the case bottom.

4. Remove the 4 screws fixing the PCB on the input

terminals, gently take apart the PCB and reverse it.

5. Remove the fuse by gently prying one end loose,

then take out the fuse from its bracket.

6. Install ONLY replacement fuses with the identical

type and specification as follows and make sure the fuse is fixed firmly in the bracket. Fuse 1:

Fuse2:

7. Rejoin the PCB and the case top, and reinstall the

4 screws.

8. Rejoin the case bottom and case top, and reinstall

the 3 screws and 3 rubber feet.

Replacement of the fuses is seldom required. Burning of a fuse always results from improper operation.

1A,250V fast type glass fuse, 5x20mm. 10A,250V fast type glass fuse, 5x20mm.

Model UT70C: OPERATING MANUAL

Receiving Data

Transmitting Data

Data T erminal Ready

Grounding

Data Set Ready

Request to Send

Clear to Send

TX DTR GND DSR

RTS CTS

3 2

7 6 4 5

2 3 4 5 6 7 8

RS232C Serial Port (1)

A. RS232C Port Cable

The

Meter

Computer

D-sub

9 Pin Male

D-sub 9 Pin

Female

D-sub

25 Pin

Female

Name

Remark

B. Setting of RS232C Serial Ports

Default of RS232C serial port for communication is set as: Baud Rate 9600 Start bit 1 (always 0) Stop bit 1 (always 1) Data bits 8 Parity Odd None

Model UT70C: OPERATING MANUAL

RS232C Serial Port (2)

C. System Requirements for Installing the UT70C Interface Program

T o use UT70C Interface Program, you need the following hardware and software: l An IBM PC or equivalent computer with 80586 or

higher processor and 640 x 480 pixel or better monitor.

l Microsoft Windows 95 or above. l At least 16 MB of RAM. l At least 8MB free space in hard drive. l Can access to a local or a network CD-ROM. l A free serial port. l A mouse or other pointing device supported by

Windows.

Please refer to the included CD-ROM "Installation Guide & Computer Interface Software" for installing and operating instructions of the UT70C Interface Program.

~ END ~

This operating manual is subject to change without notice.

Model UT70C: OPERATING MANUAL

Manufacturer: UNI-TREND TECHNOLOGY(DONG GUAN)LIMITED Address: Dong Fang Da Dao, Bei Shan Dong Fang Industrial Development District, Hu Men Town, Dong Guan City, Guang Dong Province, China Headquarters: Uni-Trend International Limited Address: Rm901, 9/F, Nanyang Plaza 57 Hung To Road Kwun Tong Kowloon, Hong Kong Tel: (852) 2950 9168 Fax: (852) 2950 9303 Email: info@uni-trend.com http://www.uni-trend.com

Model UT70C: OPERATING MANUAL

UNI-T UT70C Operating Manual

Specifications and Main Features

Frequently Asked Questions

User Manual