NVIS 61T User manual

Dual Display Multimeter
Nvis 61T
Product Tutorials
Ver. 1.1
Designed & Manufactured by:
Nvis Technologies Pvt. Ltd.
141-A, Electronic Complex, Pardesipura, Indore - 452 010 India,
+ 91-731 4211500, : [email protected], : www.nvistech.com

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Dual Display Multimeter
Nvis 61T
1. Safety Instructions 3
2. Introduction 4
3. Features 4
4. Technical Specifications 5
5. Front Panel Control 10
6. Operating Instruction 17
7. Maintenance 29
8. Warranty 33

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Safety Instructions
Read the following safety instructions carefully before operating the instrument. To
avoid any personal injury or damage to the instrument or any product connected to it.
Do not operate the instrument if suspect any damage within.
The instrument should be serviced by qualified personnel only.
For your safety:
Use proper Mains cord : Use only the mains cord designed for this instrument.
Ensure that the mains cord is suitable for your
country.
Ground the Instrument : This instrument is grounded through the protective
earth conductor of the mains cord. To avoid electric
shock the grounding conductor must be connected to
the earth ground. Before making connections to the
input terminals, ensure that the instrument is properly
grounded.
Observe Terminal Ratings : To avoid fire or shock hazards, observe all ratings and
marks on the instrument.
Use only the proper Fuse : Use the fuse type and rating specified for this
instrument.
Use in proper Atmosphere : Please refer to operating conditions given in the
manual.
1. Do not operate in wet/damp conditions.
2. Do not operate in an explosive atmosphere.
3. Keep the product dust free, clean and dry.

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Introduction
Nvis 61T is a compact ready to use Dual Display Multimeter. This is useful for
measuring voltage, current, resistances, or frequency. It is also used for testing the
diode & continuity. The Dual Display Multimeter has 5-digit high resolution mode.
The meter is designed for bench-top.
Features
A dual, Liquid Crystal Display that allows two properties of an input signal
to be displayed at the same time.
True rms AC.
Frequency measurement (volts AC Function) to greater than 300 KHz.
10µV sensitivity in volts DC.
Decibels with variable reference impedance measurement capability.
A compare mode to determine if a measurement is within, above, or below
a designated range.
Slow and Fast selectable count resolution with reading speeds of 3 and 6
reading per second respectively.
Built-in self-tests with closed-case calibration (no internal calibration
adjustment).

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Technical Specifications
This Section contains the specifications of Dual Display Multimeter.
These specifications assume:
Reading Rates:
Rate
Reading per second
Slow(S)
3
Fast(F)
5~7
DC Voltage:
Range
Resolution
Accuracy
300mV
3V
30V
300V
1000V
10µV
100µV
1mV
10mV
100mV
0.03%+3
Input Impedance : 1000MΩ at 300mV and 3V. 10MΩat other ranges.
Normal Mode Rejection : ≥60dB (at 50Hz or 60Hz)
Ratio (NMR)
Common Mode Rejection : ≥120dB (at 50Hz or 60Hz)
Ratio (CMR)
Maximum Input : 1000V peak

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True RMS AC Voltage, AC-Coupled:
Range
Resolution
Accuracy
20-50Hz
50Hz~10K
Hz
10-
20KHz
20-
30KHz
30-
50KHz
300mV
10µV
3V
100µV
2%+30
0.5%30
1%+80
5%+80
10%+15
0
30V
1mV
3%+30
1%+50
5%+50
10%+50
300V
10mV
750V
100mV
1%+30
Remark : Accuracy specifications apply to the range from 10%
to 100%
Input Impedance : 1MΩ in parallel with 0.1µF
Maximum Crest Factor : 3.0
Common Mode Rejection : >120dB at 50Hz or 60Hz (1KΩ
Ratio unbalanced resistance)
Maximum Input : 750Vrms, 1000V peak.
DC Current:
Range
Resolution
Accuracy
Input Impedance
300mA
10µV
0.1%+3
1
10A
1mA
0.5%+3
0.01
Maximum Input:
300mA, Protected with a 500mA, 250V fast blow fuse; 10A for 30 seconds
maximum. Protected with 11A, 250V fast blow fuse.

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True RMS AC Voltage, AC-Coupled:
Range
Resolution
Accuracy
20-50Hz
50Hz~2K
Hz
2-10-
KHz
10~20KHz
20~0
KHz
300m
A
10µA
2%+3
0.5%+30
1%+80
5%+
50
10A
1mA
1.5%
3%+30
Indicates that the range for frequency between 2.5 KHz
Maximum Input:
300mA. Protected with a 500mA, 250V fast blow fuse; 10A for 30 seconds
maximum. Protected with 11A, 250V fast blow fuse.
Maximum Crest Factor:
Ohm:
Range
Resolution
Accuracy
Open Circuit
Voltage
Short
Circuit
Current
300
10M
0.05%+3
2.5V
About 1mA
3K
100M
About
250µA
30K
1
300K
10
About 25µA
3M
100
0.1%+3
About0.
2.5µA
30M
1K
0.5%+3
About0.
25µA

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Maximum Input Voltage : 250V dc or rms ac on all ranges
Diode Test/Continuity
Maximum Test Voltage : ≤2V
Test Current
Approximate 1mA when measuring forward bias junction.
Continuous Resistance : ≤150Ω
Frequency:
Range
Resolution
Accuracy
0.5%+2
300Hz
0.01Hz
3KHz
0.1Hz
30KHz
1Hz
300KHz
10Hz
Frequency Range : 10Hz to 300 KHz
Applicable Function : Volts AC
Sensitivity of AC Voltage:
Frequency
Level (sine wave)
10Hz~30KHz
>30mV
10Hz~300KHz
>300mV
Environmental:
Temperature Coefficient : <0.1 times the applicable accuracy specification per
degree C for 5°C to 18°C and 28°C to 40°C.
Operating Temperature : 5°C to 40°C
Storage Temperature - :25°C to 50°C
Relative Humidity : ≤90% at 5°C to 28°C (non-condensing)
≤80% at 28°C to 40°C ≤70% at 10°C to 40°C for the
300KΩ, 3MΩ and 30MΩ ranges.

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General
Common Mode Voltage : 1000V dc or peak ac maximum from any input to earth
Size : 245mm deep, 220mm wide, 82mm high
Weight : about 2Kg
Power : about 5VA
Calibration cycle : 1 year
Warm-up time : One-hour
Reading rate : Slow
Relative humidity : Not exceeding 70% (non condensing)
Accuracy : Expressed as ± (Percentage of reading +
Digits)

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Front Panel Description
The section explains how to prepare the meter for operation, discusses general
operating features, and walks you through the basics of taking some common
measurements.
Unpacking and Inspecting the Meter:
Carefully remove the meter from its shipping container and inspect it for possible
damage or missing items. If the meter is damaged or something is missing, contact the
place of purchase immediately. Save the container and packing material in case you
have to return the meter.
Front Panel and Rear Panel:
The front panel (shown in Figure1) has three main elements: the input terminals on
the right, the display and the pushbuttons. The push buttons are used to select major
functions, ranging operations, and function modifiers. These elements are described in
detail in Section 3.
Front Panel Figure 1
The rear panel (shown in Figure2) contains the power-line cord connector the Serial
Number Label.
Real Panel Figure 2

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Adjusting the Handle:
For bench-top use, the handle can be positioned to provide different viewing angles.
To adjust its position, pull the ends out to a hard stop and rotate it to a position. To
remove the handle, adjust it to the vertical stop position and pull the ends all the way
out.
Power:
Caution: To Avoid Shock Hazard, Connect the Instrument Power Cord To a power
receptacle with earth ground.
Note: Apply the rated voltage and frequency to the meter as marked on the rear panel
of the meter.
Turing the Meter On:
To turn the meter on, press the Power button located on the lower-left of the front
panel. If the meter is being operated under battery power and you turn the meter off,
you must wait five seconds before turning the meter back on. If you do not, the meter
will not power-up.
When the meter is turned on, the full screen displays will be light while the instrument
performs an internal self-test of its digital circuitry. These tests check RAM, ROM,
A/D, and the display. The meter has passed all tests and is ready for normal operation
if an error code is not displayed.
After the meter completes the power-up sequence, it assumes the power-up
measurement configuration stored in non-volatile memory. The power-up
configuration set at the factory is shown in Table (To change the power-up
configuration, refer to “Changing the Power-up Configuration” in Section 3.)
Using the Pushbuttons:
The pushbuttons on the front panel select meter functions and operations. A summary
of basic pushbutton operations is shown in Figure3.

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Summary of Basic Pushbuttons Operations
Figure 3
Pushbuttons can be used in two ways. You can:
Press a single button to select a function or operation. Example: Press ACV to
select volts ac function.
Press a combination of buttons, one after the other. Example: Press ACV to
select volts ac function, and then press dBm to select the decibels modifier.
For more details on the uses of each button, refer to Section 3, “Operation the Meter
from the front panel.”
Selecting a Measurement Range:
Measurement ranges can be selected automatically by the meter in “autorange” or
manually by the user. In the autorange mode, the meter selects the appropriate range
for the measurement reading.
To manually select a range, press AUTO to toggle in (and out) of the manual ranging
mode, or press or. In the manual range mode, press or to up range or down range to
the desired range. For more details on ranging, refer to “Ranging” in Section 3.

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Taking Some Basic Measurements
Warning 1:
Read “multimeter safety” before operating this meter.
The following procedures describe the basics of taking common measurements from
the front panel. These procedures are provided for the user who needs to get started
quickly, but dose not want to read the rest of the manual at this time.
However, in order to take full advantage of your meter, you should read the remainder
of this manual carefully and completely.
Warning 2:
To Avoid Electrical Shock or Damage To The Meter, Do Not Apply More Than
1000V (Peak) Between Any Terminal and Earth Ground. The meter is protected
against overloads up to the limits shown in table exceeding these limits poses a hazard
to the meter and operator.
Measuring Voltage, Resistance, or Frequency:
To measure voltage, resistance, or frequency, press the desired function button and
connect the test leads as shown in Figrue4. The meter will select the appropriate range
in the autorange mode.
Measuring Voltage, Resistance, or Frequency
Figure 4

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Measuring Current:
To measure current, insert the red test lead in the mA input terminal for currents up to
330mA or in the 10A input terminal for higher current, and insert the black test lead
in the COM terminal.
1. Turn off power in the circuit to be measured. Connect the test leads as shown in
Figure5.
Measuring Current
Figure 5
2. Break the circuit (on the ground side to minimize the common mode voltage),
and place the meter in series at the point.
3. Turn on power to the circuit, and read the display, and an annunciator on the
display will indicate the units of the measurement value shown.
4. Turn off power to the circuit and disconnect the meter from the tested circuit.
Note:
After measuring high current using the 10A input, thermal voltages are generated that
may create errors when making low-level dc measurements of volts, current, or ohms.
To make the most accurate measurements, allow up to ten minutes for the thermals to
settle out.

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Diode/Continuity Testing:
The continuity test determines whether a circuit is intact (i.e., has a resistance less
than about 150Ω). To perform a continuity test, press, and connect the test leads as
shown in Figure6. The beeper emits a continuous beep when the input drops below
150Ω, and the readings for the test circuit are displayed.
Continuity Testing
Figure 6
The diode test measures the forward voltage of a semiconductor junction at
approximately 0.8mA. Readings are displayed in the 3V range at the fast
measurement rates. “OL” is displayed for voltages above 2.0V. Under normal
measurement condition, the positive pole of diode is connected with the black test
lead.
To perform a diode or transistor junction test, press to select the diode function. Then
connect the test leads across the diode as shown in Figure7.

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Diode Testing
Figure 7
Notice how the test leads are placed. Reversing the polarity will reverse-bias the
diode.

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Operating Instructions
Operating the Meter from the Front Panel:
The following operations can be performed from the front panel:
Select a measurement function (DCV, ACV, DCA, ACA, Ω, FREQ, and )
Select function modifiers that cause the meter to display relative readings
(REL), minimum or maximum values (MN MX), or decibels (dBm)
Enter the Touch Hold mode (HOLD) to hold a reading on the display
Set Measurement Rate (RATE), change the rate as “F”(Fast) or “S”(Slow)
Take a measurement and compare (COMP) it to a setting value
Select the manual or autorange mode (AUTO), up range or down range
manually to desired range
Turn on or turn off the back light (when arrive the setting time the back light can
automatically off)
Power-on or off the power supply (Power)
These operations are described in remainder of Section 3.
Display:
The meter has a 5-digit, Liquid Crystal Display (Primary Display) and a 4-digit,
Liquid Crystal Display (Secondary Display). The display shows measurement
readings, measurement units and messages. Shown in Figure8.
Display Annunciators Figure 8

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Input Terminals:
The input terminals, shown in Figure9, are located on the right of the front panel.
Input Terminals Figure 9
The meter is protected against overloads up to the limits shown in Table
Exceeding these limits poses a hazard to both the meter and operator.
Function
Input Terminals
Maximum Input
V
Vand com
1000Vdc on all ranges
V~ and Freq
Vand com
7250V ac rms, 1000V peak on
all ranges
mA and mA~
mA and com
500mA dc or ac peak
A~ and A~
10A and com
10A dc or ac rms

Vand com
250V dc or ac rms on all ranges
Vand com
250V dc or ac rms on all ranges
All functions
Any terminal to earth
1000V dc or ac peak

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Selecting A Measurement Function:
Press a function button, shown in Figure10, to select a measurement function.
When you select a function, annunciators turn on to indicate the function selected.
Rang and full scale values are summarized in Table for voltage, current, ohms and
frequency.
Function Select Buttons Figure 10

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Function
Range
Full scale
Information
V~ and
300mV
330.00mV
760V ac. rms
3V
3.3000V
30V
33.000V
300V
330.00V
1000V
1010.0V
mA~ and mA
300mA
330.00mA
A~ and A
10A
11.000A
Resistance
300
330.00
3K
3.3000K
30K
33.000K
300K
330.00K
3M
3.3000M
30M
33.000M
Frequency
300Hz
330.00Hz
Outo range for
Frequency
3KHz
3.3000KHz
30KHz
33.00KHz
300KHz
330.00KHz