Laboratory for Electrical Measurements and Instrumentation (LEMI)

Laboratory for Electrical Measurements and Instrumentation (LEMI)

Lab activity

The Laboratory performs the measurement and calibration of a part of electric quantities (voltage, current, resistance, power), electric measurement of non-electric quantities (deformation, displacement, force, pressure, temperature, sound and noise, vibrations), in static and dynamic areas, as well as estimating the measurement uncertainty. The use of Labview program package enables the development of virtual measurement systems with system data acquisition and calibration of measurement chain and virtual instruments. The Laboratory has been developing technologies of program design and 3D objects production.

Head of the Lab: This email address is being protected from spambots. You need JavaScript enabled to view it., Prof., PhD

Services:

  • Deformation measurement using strain gauges
  • Measurement of electrical power and/or energy
  • Measurement of range in which the current voltage or power strength changes over time
  • Precise measurement of voltage, current, resistance
  • Design and implementation of measurement systems
  • Estimation of measurement uncertainty
  • Calibration of temperature sensors
  • Calibration of lvdt displacement sensor
  • Measurement of sound and noise
  • Microphone calibration
  • Vibration sensor calibration
Analytical procedure and test method
Analitic procedureAnalitic procedure

Test method


 

 

 

 

 

 

 

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 Small and medium sized equipment
Name inventory
Tech.characteristics Application Image

6.5 digit Precision Multimeter 8846A

DCV accuracy up to 0,0024 %.
DCV 100 mV – 1000 V, ACV 100 mV – 1000 V,
DCA 100 μA – 10 A, ACA 100 mA – 10 A,
Resistance 10 Ω – 1 GΩ, Frequency 3 Hz – 1 MHz,
Capacitance 1 nF – 0,1 F, Temperature -200 °C to  600 °C.
Using RS-232 or GPIB bus can be connected to a computer and controlled with a Labview program of Fluke program.

Measurement of electric voltage or current, load resistance, measurement of signal frequency and period, measurement of capacitance and temperature.

Multimetar

6.5 digit Precision Multimeter 8845A

DCV accuracy up to 0,0035 %,
DCV 100 mV – 1000 V, ACV 100 mV – 1000 V,
DCA 100 μA – 10 A, ACA 100 mA – 10 A.
Resistance 100 Ω – 100 MΩ, Frequency 3 Hz – 300 kHz.

Measurement of electric voltage or current, load resistance, measurement of signal frequency and period, measurement of capacitance and temperature.

Multimetar 2

4.5 digit Multimeter UT71E

DCV accuracy (0.025 %+5d).
DCV 400 mV – 1000 V, ACV 4 V – 1000 V,
DCA 400 μA – 10 A, ACA 400 μA – 10 A,
Resistance 400 Ω – 40 MΩ, Frequency 40 Hz – 400 MHz,
Capacitance 40 nF – 40 mF, Temperature -40 °C do 1000 °C.
Power of single phase load, up to 2500 W.
Using USB can be connected to a computer and controlled with a program.

Measurement of electric voltage or current, load resistance, measurement of signal frequency and period, measurement of capacitance, temperature and power.

Multimetar 3

3.5 digit Multimeter M3900, 12 pieces

DCV accuracy (0.5 %+1d).
DCV 200 mV – 1000 V, ACV 200 mV – 750 V,
DCA/ACA 20 μA – 20 A,
Resistance 200 Ω – 20 MΩ.

Measurement of electric voltage or current and load resistance.

Multimetar 4

Multimeter High Voltage Probe for a 20 kV

DC do 40 kV.
AC do 28 kV RMS.
Accuracy ± 2 % (20 kV), ± 3 % (20 kV – 40 kV).

Measurement of DC and AC high voltages.

Visokonaponska sonda

GPIB Interface for communication of computer and instruments

GPIB to USB.

Communiction of instrument with computer.

Gibt

RS 232 Interface for communication of computer and instrument, 3pieces

RS 232 to USB.

Communiction of instrument with computer.

RS 232

Miniature Reference Temperature Thermistor Probe 5665

0 °C do 100 °C.
Točnost ±0,01 °C.

Calibration of temperature probes.

Sonda

Temperature thermistor probe USP8528-ND, 8 pieces

-55 °C to 125 °C.
Accuracy ±0,2 °C (25 °C to 80 °C).

Temperature measurement of liquids.

Temperaturna sonda za uranjanje

Logger Hygrothermometer NT2-D

0 – 100 % RH, -30 °C do 70 °C.
Accuracy 1.5 %RH, 0.2 °C.

Measurement of air temperature and humidity.

Higrotermometar

Data acquisition measurement card NI PCI 6281

8 differential/16 referenced input channels with 18 bits resolution, 2 analog output channels with 16 bit resolution, 24 DIO, measurement ranges from ± 100 mV to ±10 V. Sample rate 650 kS/s one channel, multichannel 500 kS/s.

Temperature measurement, measurement of deformations, measurement of electric detonators properties.

Mjerna kartica

Four channel oscilloscope WaveRunner 6030, 350 MHz

Analog bandwidth 350 MHz @ 50 Ω, rise time 1 ns, 8 bits of resolution on 4 channels.

Measurement of fast changing signals, voltage, current of transducer signals (e.g. strain gauges, …).

Osciloskop

Oscilloscope High Voltage Probe for a 20 kV

Max. voltage 20 kV  including  peak AC,
max. 14 kV RMS AC (50 Hz/60 Hz).
Max. 40 kV peak pulse.
Bandwidth 100 MHz.

Measurement of static and dynamic high voltage signals.

Visokonaponska sonda za osciloskop

Transducer MI400

Measurement of more than 50 different power source parameters (V, A, kW, kVA, malfunction, power factor, Hz,…) with three analog outputs and communication with computer.
Accuracy class 0.5

Measurement of power supply properties.

Pretvornik

Precission current shunt CS-10, with temperature sensor

Max. current 10 A,
resistance 0,1 Ω.
Accuracy 0,01 %.
DC/AC difference 0,01 % to 20 kHz.

Measurement of DC, AC or pulse currents. Reference for other current measuring devices. Measurement of firing pulse of electric detonators.

Precizni strujni shunt

Current shunt SB 101, 2 pieces

Max. current 30 A,
resistance 3.33 mΩ.
Accuracy 0.5 %.

Measurement of DC, AC or pulse currents. Measurement of firing pulse of electric detonators.

Strujni shunt

Wideband Current Transformer 2-0.1W

Output (V/A) 0.1. Accuracy 0.5 %
Max. current peak 5000 A. Max. rms AC current 65 A. Rise time
20 ns. Frequency 1 Hz – 20 MHz.

Measurement of electric current, powers (P, Q, S) and power factor of monophase load can be calculated. Measurement of high voltage conductor currents.

Strujni transformator

Wideband Current Transformer model 6600

Output (V/A) 0.1. Accuracy 1 %
Max. current peak 2000 A. Max. rms AC current 40 A. Rise time
5 ns. Frequency 25 Hz – 120 MHz.

Measurement of electric current, powers (P, Q, S) and power factor of monophase load can be calculated. Measurement of high voltage conductor currents.

Sirokopojasni strujni transformator

Wideband Current Transformer model 6585

Output (V/A) 0.1. Accuracy 1 %
Max. current peak 500 A. Max. rms AC current 10 A. Rise time
1.5 ns. Frequency 400 Hz – 250 MHz.

Measurement of electric current, powers (P, Q, S) and power factor of monophase load can be calculated. Measurement of high voltage conductor currents.

Sirokopojasni strujni transformator

Current Transformer MSZ 1576, 10 pieces

Measurement ranges 15 A, 50 A, 100 A, 200 A, 300 A, 400 A, 600 A.
Accuracy 0.2 %

Measurement of rms AC currents.

Mjerni transformator

Multichannel Arbitrary DC Power Supply Unit HM8143

Two outputs (0 V– 30 V)/2 A and output with fixed voltage
5 V/2 A.
Two outputs can work as amplifier with amplification of 3.
One channel can work as signal generator (12 bits/4096 points) with output current <2 A.

Power supply of loads or sensors/transducers that need regulated voltage or current for operation.

Visekanalno upravljivo DC napajanje

High voltage DC power source MK40P1.8.

Type MK, up to 40 kV (5 % to 100 %), 75 W, 1.8 mA.

For Detonator sensitivity testing to high voltage disharges.

Viokonaponski izvor

Stereo sound and noise recorder TASCAM US-122

Sample rate 48 kHz, 24 bit resolution,
16 MIDI I/O channels.

Sound or noise signals recording which enables saving data to the computer and later analysis.

Uređaj za dvokanalno snimanje zvuka

Measurement condenser microphone ECM 8000, 2 pieces

Impedance 200 ohms,
sensitivity 70 dB,
freq. response 20 Hz – 20 000 Hz,
phantom power +15 V to 48 V,
gold plated XLR connector.

Omnidirectional ultra linear microphone for measurement and recording applications.

Mikrofon
Teaching in the laboratory

 Teaching in the laboratory (students' practical work)

Course title

ISVU ID number

Mandatory or Elective course

Number of hours of practical work in the Lab

Fundamentals of Electrical Engineering

27286
262448

Mandatory

8

Fundamentals of Electrical Engineering

26977

Mandatory

8

Electrotechnology in Mining

27325
262496

Elective

10

Automation in Mining

253240

Elective

10

 Measurement Technology

262499

Elective

10

Teaching in the laboratory (Students scientifice research)
Teaching in the laboratory Students scientifice research)    
  Name and surname of student Tesis title

 

BSc thesis

David Jakovljević
2021.

RECONSTRUCTION OF MEASUREMENT DATA FROM IMAGE INTO TABLE FORMAT

Filip Antolaš
2021.

DEVELOPMENT OF A DEVICE FOR MEASURING THERMAL CONDUCTIVITY OF ROCKS

Filip Antolaš
2019.

DEVELOPMENT OF ARDUINO VOLTAGE LOGGER USING THE THINGSPEAK PLATFORM

MSc thesis

Dario Šamec
2023.

THE ISSUE OF CALIBRATING SENSORS FOR ROCK CUTTING SIMULATION

Karlo Weiser
20201.

LOCATION DETERMINATION FOR OPTIMAL SUBTERRANAEAN NAVIGATION WITH APPLICATON OF SGS

Mateja Katalinić
2021.

ATYPICAL VALUES IN MEASURING SEISMIC IMPACTS OF BLASTING

Kristijan Sekulić
2020

APPLICATION POSSIBILITIES OF THE ARDUINO DEVICES AND 
THEIR PERFORMANCE IN ANALOG SIGNAL MEASURING

Bruno Ćesić
2020.

DJIKSTRA ALGORITHM COMPLEXITY AND ITS APPLICATION IN
UNDERGROUND NAVIGATION DEVICE FOR UNDERGROUND FACILITIES

Luka Čolić
2019.

EXPLOSION PROTECTION ENCLOSURE TESTING 'Ex d'
Projects in the laboratory

Projects in the laboratory in 2016/2017 

Scientific research (including University support)

Expert projects

Development of systems for measuring parameters and monitoring working conditions in mining and similar facilities 2025, 2024..

Measurements on the control system for heater control in the field test site Rudnik Sv. Barabara, Rude, Samobo 2025r

Development of computer odel sin the processes of extraction and transportation of mineral raw materials 2022., 2021.,

 

Optimization of mineral resource exploitation by increasing energy efficiency 2020., 2019.