Meatest M143 User manual

Multifunction calibrator M142 is calibrator of electric quantities for application in calibration
laboratories and in production lines where voltage, current, resistance, capacity and frequency meters
are manufactured. Load capacity of the voltage output is 30 mA - enough for most high-consumption
analogue power-meters. Installed harmonic and non-harmonic shape signals allow for testing meter
sensitivity to distorted signals by a signal with various crest factor. Frequency modes, suitable for
calibration of multimeters and time bases of oscilloscopes, have adjustable 6-digit frequency, amplitude
and duty ratio of the output signal. The calibrator can measure temperature with TC and RTD
temperature sensors to show it on display or use for cold junction compensation.
Main control segments of the calibrator are:
1. Output terminals - Output signal is connected to the output terminals. Current ranges are
connected to A+I / -I terminals. Voltage, resistance, TC sensor simulation and frequency
functions are available at V Hi / Lo terminals.
2. Display
3. Numerical keypad - Numerical values can be entered from the keyboard. ENTER button is used
to confirm the selection. ESC button can be used to cancel the entry.
MENU button - Open Main menu of the instrument (parameters setting).
Select button –Select value you want to change.
ESC button –Exit / Cancel button.
Enter button –Confirmation button.
4. Button for function selection.
5. OPER button - Turns output ON/OFF according to selected function and parameters.
6. Cursor buttons - The keyboard includes two buttons (<, >) which allow the cursor to be set to
the required position at the display. Remaining two buttons (, ) allow the user to increase or
decrease the number at the cursor.
7. Display button output/input - Three buttons located under the display has alternative meaning.
Their actually valid function is labeled on the display.
8. Auxiliary output/input - The auxiliary connector is aimed as input for Opt 143-90 external
Pt1000 temperature sensor. Another function is output of RTD temperature sensor simulation
using Opt 143-60.

Display is divided into several sections with following meaning:
1. Main field - Main value. Can be edited via numerical input or cursor keys or rotary. Symbol on
the right represents signal shape.
2. Time field - displays time
3. Information field - In the field some additional information are displayed:
-Output terminals - Symbol of output ON (rectangle symbol) or output OFF. In parallel LED
diode is turning on/off above the OPER button.
-Local/Remote control - In remote control label REM is displayed, in manual mode label
LOCAL is shown.
-Output current simulated by current coil Opt. 140-50, if the coil is connected to the output
current terminals. Access to this function is through SETUP MENU.
-Grounding of Lo/-I terminals.
-Selected TC temperature sensor in TC sensor simulation mode.
4. Accuracy field - Currently valid accuracy of the main parameter. It is calculated from
specification of the calibrator and it is displayed in %.
5. Display button field - Labels related to the display buttons. Meaning is as follows:
6. Auxiliary parameter field - Auxiliary parameters of the output signal are displayed. To these
parameters belong:
-Set relative deviation in % (max 30.000 %)
-Frequency of AC voltage/current
-Temperature of cold junction in TC temperature sensor simulation mode, type of TC sensor

There are located power line entry module with line socket, fuse, power line voltage selector and mains
switch, RS-232 connector (GPIB connector optionally), grounding post and model plate number with
serial number. The grounding post is galvanically connected to metal parts of housing and protection
earth terminal in power line socket
Between output terminals and protection earth potential following maximal voltages are allowed:
Hi - GND: 1100VRMS
+I - GND: 10VRMS
Lo - GND: 10VRMS
- I - GND: 10VRMS
1. Model plate
2. Fan outlet cover
3. Power cord module
4. Grounding post
5. GPIB connector (optional)
6. RS-232 connector
Every M143 Portable Multifunction Calibrator delivery includes following items:
-USB stick with user manual 1 pc
-Factory calibration certificate 1 pc
-Power cord (with European E-type plug, feel free to ask for other types when ordering) 1 pc
-Spare fuse 1 pc
-RS232 cable 1 pc
-Test cable 1000 V / 20 A 2 pcs
Following accessory is not part of standard delivery and can be extra ordered:
-Option 143-90 Pt1000 Temperature sensor
-Option 143-60 Cable adapter

The calibrator can be integrated into automated calibration systems (ATS) and generally controlled from
remote computer via following remote control interfaces:
-RS232
-GPIB (IEEE488) (option)
When controlled remotely, maximum ratings of calibrator’s output signals as well as all other
specifications are the same as in manual mode.
Meatest software package WinQbase + Caliber is recommended for best automationresults. This system
is designed for automated and semi automated calibrations of digital and analogue meters including
uncertainty calculation, result evaluation and certificate printing according to ISO 17025 standard.
Only one interface can be used for communication at any given time. Default active interface is RS232,
other interfaces can be selected in MENU. To establish connection between the calibrator and computer,
set interface settings in your computer accordingly:
-COM port see available COM ports in Windows Device Manager
-Baudrate RS232 according to MENU->Interface->RS232 Baudrate (9600 by default)
-Data bits 8
-Stop bits 1
-Parity None
-Handshake (XON/XOFF) Off
-GPIB Address according to MENU ->GPIB Address (2 by default) (option)
See M143 SCPI manual for complete SCPI reference, more details on communication setup and
troubleshooting.

Inspect package contents when unboxing the calibrator for the first time. See chapter 1.3 for complete
list of accessories.
Place the instrument on a level surface before powering on and let it stabilize for at least one hour if the
instrument has been stored outside of reference temperatures beforehand.
The instrument has been designed according to IEC 61010-1 + A2 amendment of sthe standard. Safety
is ensured by design and by use of specific components. The manufacturer is not liable for the damage
caused by modification of the construction or replacement of parts with non-original ones.
Safety symbols used on the equipment:
Warning, risk of danger.
Warning - risk of electric shock. Hazardous voltage above 50 V DC
or AC might be present.
Protective earth.
To prevent possible electrical shock or personal injury:
-Read carefully safety information before you use the Product.
-Do not alter the Product and use only as specified, or the protection supplied by the Product can be
compromised.
-Do not use the Product if it is altered or damaged.
-Use this Product indoors only.
-Use power cord approved for local mains voltage and plug configuration and rated for the Product.
-Keep hands away from all Product terminals and exposed metal cable parts during operation. High
voltage on those may be cause death or serious injury.
-Do not connect the calibrator to other voltage than set by the voltage selector.
-Do not block the vent openings located at the rear panel, bottom panel and prevent dust and
moisture contamination.
-Whenever possible ground Lo output terminals (GndU On, GndI On).
-Do not overload the power stages by leaving the calibrator switched on with the load connected for
a long time especially on 20 A current range and 1000 V voltage ranges.

The calibrator is designed for operation from 115/230 V –50/60 Hz power line voltage. Before the first
connecting the calibrator to the mains, check the position of the mains voltage selector located at the
rear panel. If the set voltage differs from your power line voltage power line selector must be switched
over as described below:
-Insert flat end of a screwdriver to the slot in power line socket on the rear panel. Wind with the
screwdriver slightly to pull out the holder with fuse and selector contacts.
-Place the contacts in such position, that correct power line voltage can be read in the rear window.
-Push the holder back to the power line socket. In the window correct voltage (115 or 230 V) must
be seen. Use position 115 V for nominal mains voltage 110 to 130 V and 230 V position for range
220 to 240 V.
Plug one end of the power cord into connector on the rear panel and connect the other end of the power
cord into a wall outlet. Turn the calibrator on with mains switch right next to it.
The calibrator works after it is switched on and the initial checks complete. Specified parameters are
only guaranteed after the instrument warms up. During this period, the instrument cannot be calibrated.
The display shows “cannot access the calibration” message if calibration is attempted during this period.
Push FUNC button to see table with available functions. Requested function can be selected using cursor
buttons or directly by pushing numerical button with number of the function, with confirmation by
ENTER. Following functions are available:
1. DC voltage
2. DC current
3. AC voltage
4. AC current
5. Resistance
6. Frequency
7. TC temperature sensor simulation
8. RTD temperature sensor simulation (optionally)
Once a function is selected, you can change the main value as well as auxiliary output parameters
Function parameters can be edited in three ways:
-Numeric keypad. Write a value directly and confirm either by softkey with appropriate unit or
ENTER button to set value in base unit (for example V).
-Cursor keys. Push or buttons to increment/decrement selected digit by one. Move through
parameter digits using < and > buttons.
-Softkeys. Values of most parameters can be also changed by softkeys x10 and :10, which change
value by order of magnitude and +/- softkey which switches polarity or Shape softkey that will
change shape of signal.
Described methods change the main parameter by default. If there are any other parameters on display,
you can switch between them using (SEL) select button.

Calibrator output can be turned on by pushing OPER button. Pressing it again turns output off. Output
turns off automatically on calibrator startup and function switch. Output state is indicated by LED light
above OPER button as well as rectangle on the top right side of the display when output is ON. When
output is off - symbol OFF will be in that place instead.
Voltage over 100 V is indicated also with acoustic interrupted signal.
If an obvious failure occurs during the operation (e.g. the display is not lit, the fan is not turning), the
calibrator must be switched off immediately. First, check the fuse located in the power cord receptacle.
Procedure is following:
-Remove the end of power cord from the mains connector at the rear panel.
-Insert the blade of a flat screwdriver into the opening cut in the mains voltage selector and pry out
the fuse holder.
-Remove the fuse. Replace it with new fuse of the same rating if the fuse was broken.
-Replace the fuse holder, reconnect the power cord and switch on the calibrator. If the problem
persists, contact the manufacturer.
If an obvious fault is evidenced, e.g. a measurement range or an operating mode is not functional, the
user cannot correct the fault. Contact the manufacturer.
Hidden faults can cause different symptoms and be caused by different causes. Usually, they cause
instability of some parameter. Hidden defects can be caused by unacceptable distortion, degraded
insulation etc. In this case contact the manufacturer.
Sometimes it seems that the calibrator has hidden defect, when the rules for correct operation are not
adhered to. In this case, the fault is caused by the operator. Most frequent cases of false “hidden defects”:
-mains voltage out of tolerance limits or unstable
-wrong grounding of the measurement circuit (bad connection of the ground terminal of the mains
outlet, or several ground connections when grounding loops are formed)
-proximity to sources of intensive influence, whose products are spread through the mains or
propagated by the electromagnetic field
-strong electrostatic or electromagnetic field which can cause major instability during calibration
using higher impedance.

Multifunction calibrator allows other, less frequently used parameters to be set. Setup menu is used to
set these parameters. Setup menu is opened by pressing MENU display button. If output terminals are
connected, they are disconnected and the following display appears:
Use or cursor button to browse the menu options. Active option is always inverted and when
changed, the descriptions of display buttons change as well. Display buttons show how the parameter
can be set. Press ESC button twice to save the parameters when new setting is completed. New setting
is saved and refreshed when the calibrator is switched off and switched on. Setup menu offers following
options:
Coil x50 . . . . . . OFF
Gnd . . . . . . . . ON
Temp. scale . . . ITS90
Temp. unit . . . . . . oC
RJ Temp. . . . . . FIXED
Calib

Calibration menu contains internal calibration constants and other tools for device adjustment and is
therefore password protected. See chapter 6 for more details on M143 adjustment.

The multifunction calibrator provides calibrated DC and AC voltage. Output terminals for voltage
ranges are labeled “ Hi “ and “ Lo “ at the front panel. Depending on the setting of the calibrator, voltage
up to 1000 Vrms can be present at the terminals. Real voltage ranges are as follows:
DC voltage range from 0 to 1000 V.
AC voltage range from 1 mV to 1000 V
-Press FUNC button on the calibrator and select DC or AC voltage mode. The display shows the
following data:
main data of set voltage
relative deviation
accuracy of output voltage
frequency (when AC voltage is generated)
-Set the desired value of voltage, including polarity when necessary, frequency and relative
deviation. The signal is yet not connected to the output terminals. The information section of the
display shows the symbol OFF which informs about the disconnection of output terminals.
-Press OPER button.
-Red LED is lit above the OPER button to signal the connection of the signal to the output terminals;
the information section of the display shows rectangle symbol.
-Calibrated voltage corresponding to set parameters is present at the output terminals.
When output voltage over 100 V is selected, the information section of the display shows the symbol
which informs that a life-threatening voltage will be present at the output terminals. If the output
terminals are currently connected, they will be disconnected when output voltage over 100 V is selected.
OPER button must be pressed to reconnect the output signal to the output terminals. After the OPER
button is pressed, an interrupted beep is sound, OPER LED is lit and the information section of the
display shows the symbol notifying the user about the connection of the dangerous output signal to the
output terminals.
Voltage, polarity, frequency, absolute and relative deviation can be set without the outputs being
disconnected. The output terminals are automatically disconnected when changing between AC and DC
ranges or when changing the function mode.
If the output terminals are overloaded or short-circuited in the voltage mode, the calibrator disconnects
the signal from the output terminals and reports „Overload U output“ error.
It is not possible to disconnect the output voltage using the buttons located at the front panel when the
calibrator is in remote mode! The calibrator must be first switched to local control mode by pressing the
LOCAL button and then the output terminals can be disconnected!
Thanks to low output impedance and high output current, the calibrator can be used for calibration of
analogue voltmeters and millivoltmeters having low input impedance. Voltage output is connected to
Hi/Lo terminals. The calibrator does not allow the four-terminal connection of the instrument to be
calibrated.
It is not recommended to connect non-standard load to the voltage output. The calibrator is designed as
a source of precise voltage for calibration of voltmeters. Output terminals should be loaded with high

and real impedance. Although the output is fitted with fast electronic and microprocessor protection,
high capacitance or inductance loads can lead to oscillations of output amplifiers and result in damage.
The instrument to be calibrated can be connected directly to the front panel terminals with test cables,
which are a part of basic delivery. If L terminal of device under test is not grounded it is recommended
to ground Lo terminal on the calibrator GND ON, see chapter SETUP MENU.
Connect voltage input of the multimeter to the M143/143i voltage output:
The multifunction calibrator provides calibrated DCand ACcurrent. Output terminals for voltage ranges
are labeled “+I“ and “-I“ at the front panel. The terminals can carry high current and are the only
terminals to which the calibrated object can be connected. Depending on the setting of the calibrator,
current up to 20 Aef can be driven by the terminals.
DC current range from 0 to 20 A in M143 from 0 to 2 A in model M143i
AC current range from 1A to 20 A in M143 from 1A to 2 A in model M143i
When Current coil 50/25 (option 140-50) is used, maximal simulated AC current is 1000 A (100 A in
M143i).
-Press the button FUNC and select AC or DC current mode. The display shows the following data:
main data of set current
relative deviation
accuracy of output current
frequency (when AC current is generated)
-Set the desired value of current, including polarity when necessary, frequency and relative
deviation. The signal is yet not connected to the output terminals. The information section of the
display shows the symbol OFF which informs about the disconnection of output terminals.
-Connect the load or short the output terminals labeled +I, -I.
-Press OPER button.
-Red LED is lit above the OPER button to signal the connection of the signal to the output terminals;
the information section of the display shows rectangle symbol.
-Calibrated current corresponding to set parameters is driven by the output terminals.
-If COILx50 function is activated (see below - Setup functions menu), the optional 50-turn coil must
be connected to output terminals. The calibrator can be used to calibrate clamp ammeters to 100 A
ammeters.

Note: M143/143i current power stage is cooled by fan with variable speed. Variable noise can be
heard when set to AC/DC current function, especially at range 20A.
Note: M143 can supply external load for limited period in range 10A to 20A.Default period is 5
minutes at 20 A and 15 minute at 10 A. It can vary depending on previous load conditions.
Full recovery to starting condition takes about 5 minutes.
When external circuit connected to current output terminals is disconnected or there is higher voltage at
the load than permitted, the calibrator disconnects the output terminals and displays „Overload I output“
message. The same message can be displayed when 50-turn coil is used for AC current output at
frequencies above 80 Hz. It depends on the set current and the type of ammeter connected.
All DC and AC current ranges are connected to calibrator’s +I/-I terminals.
When using the current output under heavy load (10 to 20 A), the runtime is limited to 0 to 60 s. The
runtime depends on the set current and it is controlled by the microprocessor. The user cannot extend
the runtime; if longer runtime is required, the output terminals must be unloaded, some time must elapse
(for example1 min.) and the load can then be connected again.
When feeding 0.2 to 2 A current to the output terminals, the output voltage must not exceed approx. 2
Vef. If the current causes higher voltage on the load, the calibrator disconnects the output terminals and
displays an error message.
When ammeters are being calibrated using currents over 1 A, it is important to connect the terminals
properly, paying attention both to the calibrator’s output terminals and the instrument’s input
terminals. Excessive contact resistance can heat up the terminals and cause calibration errors.
Excessive and unstable contact resistance has non-linear characteristic and can distort the output AC
current.
It is not recommended to connect non-standard load to the current output. The calibrator is designed
for use in calibration of ammeters. Output terminals should be loaded with low and real impedance.
Although the output is fitted with fast electronic and microprocessor protection, high capacitance or
inductance can lead to oscillations of output amplifiers and result in damage.
If L terminal of the instrument to be calibrated is not grounded, the Lo terminal should be grounded
GND ON, see „Setup menu“ chapter.
Connect ammeter to the output current terminals:

Optional current coil can extend the calibrator’s current range to 1000 A. The coil can be used for
calibration of both DC and AC ammeters. The clamps of the ammeter must be positioned in angle 90o
to the coil. When using the current coil, no steel or other magnetic objects must be present in the vicinity
(50 cm) of the current coil, as they would deform the magnetic field and cause big calibration error.
Connection of current coil:
The multifunction calibrator can generate non-harmonic periodic signals with predefined shape. To
allow the setting of a non-harmonic output shape, the calibrator must be switched to ACV or ACI mode.
In both cases, an indication of the type of output shape is displayed beside the main set value. Press the
display button SHAPE to change the shape of the output signal.
The calibrator can generate the following shapes:
-SINE sinus (harmonic)
-PWM SYM square wave –symmetrical, with adjustable duty cycle
-RAMP A ramp, symmetrical positive
-RAMP B ramp, symmetrical negative
-TRIANGLE triangular, symmetrical
-LIM SINE sinus with amplitude limitation (truncated sin) with defined distortion
k=13.45%
Generation of non-harmonic signals has some limitations:
-non-harmonic signals can be generated in frequency range 20 Hz to 80 Hz
-maximal non-harmonic current is 2A, maximal voltage is 10V
-Select AC voltage or AC current mode.
The main section of the display shows the following data:
main data of set current or voltage, unit of measurement
relative deviation
frequency
selected SHAPE of the output signal
-Keep pressed SHAPE display button to select the desired shape of the output signal:
The output terminals are automatically disconnected when the shape of the output signal is
changed. Relative deviation is reset.

When non-harmonic output shape is selected, the display shows additional information:
-Besides the main amplitude data, „pk“ index is displayed, notifying that the displayed main value
is the peak value.
-Symbol which displays the shape of the output signal is displayed.
Multifunction calibrator is equipped with fix resistance positions values with decade nominal values.
The positions are created with stable resistors. Their value cannot be adjusted. The resistance feature is
available on Hi –Lo terminals in two-terminal connection.
Resistance range is 10, 100, 1k, 10k, 100k, 1M, 10M, 100M.
-Press FUNC button and select resistance function.
The display shows the set resistence:
calibration value of set resistance in 
accuracy of the resistance
-To change the resistance value press the display button x10 or: 10.
-Press the button OPER button to connect the resistance to the output terminals; the information
section of the display shows rectangle symbol.
-Red LED is lit above the OPER button and indicates that the resistance is connected to the output
terminals.
-Resistance mode is suitable for use in DC applications and AC applications to 10 kHz.
10.0000 Vpk Λ
OFF
Local
Gnd
ACCURACY
0.30
Δ% = 00.000 %
X 10 : 10 Shape
f = 80.000 Hz
10.0059 kΩ
OFF
Local
Gnd
ACCURACY
0.015
X 10 : 10

Multifunction calibrator can generate square wave TTL leveled signal with 4 digit resolution frequency.
The signal is available in frequency mode on output terminals Hi –Lo. Frequency range is from 0.1 Hz
to 2 MHz.
Output waveform in frequency mode is always square wave with TTL amplitude 0 –5 V.
-Press FUNC button and select frequency mode.
The display shows following data:
set frequency as main parameter
relative deviation of frequency
accuracy of frequency
-Set the frequency using numeric keyboard or cursor buttons. Output signal is not yet connected to
the output terminals.
-Connect the object of calibration to left Hi and Lo terminal.
-Press OPER button. Red LED is lit above the OPER button to indicate the connection of signal to
the output connector; the information section of the display shows rectangle symbol.
Note: Output impedance in frequency mode is 50 Ωon Hi –Lo terminals.
The calibrator can be used for basic calibration of the frequency ranges of multimeters and simple
counters. The calibrator provides the following functions:
-Calibration of frequency functions up to 2 MHz using square wave signal. The function is activated
with repetitive pressing the FUNC button and selecting the Frequency mode. Only value of
frequency can be set.
-Calibration of vertical sensitivity from 1 mV to 10 V in the frequency range 1 kHz. ACV function
is used with square wave output form. Frequency and amplitude can be set.
-The instrument to be calibrated is connected to the Hi –Lo output terminals.
Multifunction calibrator can optionally simulate resistance temperature sensors.
When resistance temperature sensors are simulated appropriate resistance with value corresponding to
set temperature is connected to the output terminals on the front panel connector RTD. Connection is
four-terminal type. Use connector attached to the delivery to connect unit under test to RTD connector.
Temperature setting range: -250 to +850 °C for Pt temperature sensors
-60 to +300 °C for Ni temperature sensors
Temperature scale: ITS 90, PTS 68
Front panel RTD connector connection: D-SUB 09
10.0000 kHz
OFF
Local
Gnd
ACCURACY
0.0050
Δ% = 00.000 %
X 10 : 10

-Press FUNC button on the calibrator and select RTD sensor simulation function.
The display shows following data:
main data of temperature in °C or K
sensor type thermocouples: Pt or Ni
set value of absolute deviation in %, labeled T = xxxx.x °C (K)
the auxiliary section shows:
temperature scale type
accuracy of simulated temperature value of selected temperature sensor type
-Set the main value of temperature using numeric keyboard or cursor buttons. The information
section of the display shows the symbol OFF which means that output terminals are disconnected.
-Connect the object to be calibrated to RTD connector.
-Press OPER button. Red LED is lit above the OPER button to indicate that the output signal is
connected to the output terminals. The display shows rectangle symbol of connected output
terminals.
Note: Maximal power dissipation in the simulator is 0.2 W.
-Press Display button Type.
-Each press of the button selects Pt1.385, Pt1.392 or Ni resistance thermometer. The display shows
current setting as Pt385 / Pt392 / Ni.
For resistance temperature sensors, resistance at 0 °C labeled R0 can be set. The range is 100 to 1 k
for all types of resistance temperature sensors.
-Select the resistance temperature sensor mode and keep pressing the TAB cursor button in
numerical keyboard until [ _ _ _ _ _ _ _ ] symbols appear under the R0 coefficient value (R0 =
xxxx ).
-Set the value using numeric keyboard and confirm by pressing “ ” display button or by pressing
ENTER.
Note: For temperature scale selection ITS90 / PTS68 use SETUP menu.
250.0 oC
OFF
Local
Gnd
ITS90
ACCURACY
0.3 oC
ΔT = 000.0 oC
Type
R0 = 100.0 Ohm
Pt385