Feb 25 2019

Digital Epstein Tester Model EP400

  • admin
  • 25 February 2019

Digital Epstein Tester EP-400 is designed to measure AC magnetic properties of flat rolled magnetic materials at high frequency by using Watt-meter, Ammeter, Voltmeter and Source. Epstein bridge test method is a fundamental method for evaluating the magnetic performance of flat-rolled magnetic materials in either sheared or stress relief annealed condition. This test method is suitable for design, specification acceptance, service evaluation, and research and development.

Digital Epstein Tester EP-400 has digital controlled crystal accurate 16 Bit sine wave Generator, which provides 35 Hz to 200 Hz harmonics free non distorted power for testing of specimen. It has in built measuring meter, like Flux Voltmeter, RMS Voltmeter, RMS Ammeter, Peak Ammeter, Watt-meter and Power Factor meter with digital sampling method. These measuring devices are (temper proof) precisely calibrated to achieve high accuracy and long term stability.  Accuracy and stability of Digital Epstein Tester EP-400 is better than specified in national and international standards.  (Reference to  ASTM: 343, IEC: 60404-2, BIS: 649)

User have to just click on “START” after feeding all input parameter. Digital Epstein Tester EP-400 starts taking result for selected test points automatically. For testing at each test point,  frequency, flux volt & induction automatically set using digital sampling method by micro controller. After competition of testing, software generates report in pdf.

“Gopal Magnetic Tester” is advanced software provided with Digital Epstein Tester EP-400 for fully automatic testing. User can test a specimen with eleven different Inductions and generate complete report within fifteen minutes. Test report provides hysteresis curve, B/W, B/VA, B/Hrms, B/Hpeak, B/Ac permeability, B/peak permeability etc.. at possible points to analyze magnetic property.

USER FRIENDLY operation and multiple use of Digital Epstein Tester EP- 400, make it world leader of magnetic measurement. It has four operation modes one is standard 25 cm Bridge mode which can be operate by hardware and software both. Other three are User mode, Transformer mode and toroid mode which can only operate by hardware. USER MODE is provided as complimentary function for R&D purpose of user. 

For example user wants to test small transformer, EI core, Torrid Core, Ring type core, and any different shape of core, then user mode provide facility to set source and set required Voltage and Frequency w i t h i n I n s t r um e n t s p e c i f i c a t i o n s , a n d simultaneously displays Flux Volt, RMS Volt, RMS Amp, Peak Amp, Watt and Power Factor so user can analyses by self, what is Iron Loss, AT/m, Magnetizing force and permeability. Normally this type of operation required technical person, to calculate various parameters, like core area effective weight, Flux Volt, Watt per kg etc.


  • Basic 0.1% Accuracy @ 50Hz
  • Fully automatic testing by software
  • Auto and manual test method
  • Temper proof calibration & User mode facility
  • Long terms stability
  • 28 Push button for easy operation
  • 20 x 4 character Jumbo LCD Display
  • USB  connectivity
  • 35 Hz to 200 Hz Source
  • source capacity 500VA =1000gm, 250VA=500gm, 125VA=250gm
  • 16 Amp peak Source capacity
  • 700 Turns Standard Bridge
  • MS body
  • Protected against supply fault up to 420V (Useful when neutral short with phase)
  • Electronics over voltage & under voltage protection
  • Surge, Sparking & Harmonics Protection

Scope of Measurements

Quality Measurements of Flat Rolled Electrical Steel Sheet like CRGO, CRNGO, CRNO, HR etc...

  • Iron Loss Watt per Kg
  • Iron Loss Watt per pound
  • Ampere Turns per Meter
  • Permeability
  • B/H Curve (with Software)

Technical specification

  • Sine wave Generator =  35 to 200 Hz
  • Accuracy of frequency =   0.03% which instrument can set 
  • Source capacity =  16 Amp Peak @ 50Hz
  • Source max. Voltage =  40 Volt RMS @ 50Hz =1000gm, 20V=500gm, 10V=250gm 
  • Distortion of Sine wave =   0.025% @ 50Hz
  • Protection (Auto)Source =  16 A peak, no connection, short circuit, overload , low pf 
  • Protection of power input=  Electronics over voltage & under voltage protection
  • Input voltage = 230V @ 50 Hz 8 Amp ± 10% or 110V @ 60 Hz 12Amp ± 10% 
  • Operation temperature =  20° to 45° Celsius
  • Operation humidity =  less than 70%
  • Accuracy of Voltmeter =  0.1% True Rms Volt multiple range 8 @ 50Hz 
  • Accuracy of Flux meter =  0.1%  Rectified mean Volt multiple range 8 @ 50Hz 
  • Accuracy of Ammeter =  0.1% True Rms multiple range 8 @ 50Hz
  • Accuracy of Peak Ammeter=  0.2%  @ 50Hz
  • Accuracy of Power meter =  0.2%  From 0.15PF to 1.00PF @ 50Hz 
  • Accuracy of PF meter =  0.2% From 0.15PF to 1.00PF @ 50Hz

Specification of Bridge

  • Bridge Size = 25 cm ( 94 cm mean length )
  • Number of turns = 700 ( Primary = Secondary )
  • Specimen size = 30 x 280 to 305 mm
  • Specimen weight = 250gm to 500gm
  • Bridge weight = 7.3 Kg approx.
  • Dimension = 35 x 32.5 x 11.5 cm
  • Air flux compensating coil mounted inside the Bridge