Raytech MINI-ATOS (Automatic Transformer Observation System)

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Raytech mini-ATOS: Automatic Transformer Observation System. This precision instrument is a professional multifunctional power transformer and substation diagnostic system. It is a compact and intelligent instrument that can perform many routine routine and advanced tests such as Turns Ratio (TR), Winding Resistance (WR), Dynamic Resistance Measurement (DRM), Frequency Response of Stray Losses (FRSL), Magnetic Balance, and other diagnostic parameters. Only a one-time connection is required for nearly all functions which saves a considerable amount of time. The portable and rugged case is perfect for use anywhere on-site or in a laboratory. It is specially designed for fast and easy measurement with the well-known high precision and quality of all Raytech instruments.

SKU: Raytech MINI-ATOS Category: Tags: ,



  • Portable
  • Turns Ratio AND Winding Resistance
  • Demagnetization
  • 5 built-in temperature channels
  • Internal printer
  • Color LCD display with backlighting and touch screen
  • Panel mounted Emergency Stop Switch
  • Mounted in a rugged and lightweight case
  • 5-Year Standard Warranty


Test CurrentCharging VoltageResistance RangeAccuracy
Resistance Measurement30A and 7.5A
100v0 … 100kΩup to 0.1% ± 0.1μΩ
Power SupplyTurns Ratio RangeAccuracy
Turns Ratio Measurementup to 250VAC1 … 20 000up to 0.05%




  • Size: L: 524 mm (20.6”) W: 428 mm (16.8”) H: 206 mm (8.1”)
  • Weight: 15 kg (33 lbs.)
  • Input Power: 85 – 264VAC 47…63Hz, auto-ranging
  • Interface: 2 x USB-A 1 x USB-B / Ethernet port
  • Operating temperature: -10°C to +60°C (14°F to 140°F)
  • Storage temperature: -20°C to +70°C (-4°F to 158°F)


  • Cable Bag
  • Test Leads
  • Ground Cable
  • Power Cord
  • Paper Refill for Printer – 5 rolls Fuses
  • Stylus
  • USB Memory Stick Instruction Manual Certification Report


  • DRM – Dynamic Resistance Measurement
  • FRSl – Frequency Response of Stray Losses
  • Short circuit impedance
  • Magnetic balance
  • OLTC motor current measurement
  • Excitation current
  • Auto vector detection
  • Heat-Run
  • External Temperature Probe Safety Switch
  • Tap Control
  • Current Clamp
  • Short Circuit Clamps