Beiguang GDAT-C1 Insulating Oil Dielectric Loss & Volume Resistivity Tester

Overview

The Beiguang GDAT-C1 Insulating Oil Dielectric Loss & Volume Resistivity Tester is a fully integrated, microprocessor-controlled laboratory instrument engineered for precise, standardized evaluation of dielectric performance in transformer oils and other liquid insulating materials. It operates on the principle of high-voltage AC bridge measurement (for dielectric dissipation factor tan δ and relative permittivity ε_r) and guarded DC resistance measurement (for volume resistivity ρ_v), in strict accordance with GB/T 5654–2007 — the Chinese national standard technically aligned with IEC 60247 and functionally equivalent to ASTM D924. The system incorporates a precision three-electrode oil cup (electrode gap: 2 mm), digitally stabilized 50 Hz AC test voltage (0–2000 V), adjustable DC test voltage (0–500 V), and closed-loop temperature control (0–125 °C, ±0.5 °C accuracy) via non-contact mid-frequency induction heating. All signal conditioning, data acquisition, and real-time computation are executed using a dedicated DSP core with FFT-based noise suppression, ensuring stable, low-drift measurements under variable ambient conditions.

Key Features

• Automated dual-mode testing: Simultaneous or sequential measurement of dielectric loss factor (tan δ), relative permittivity (ε_r), and volume resistivity (ρ_v) within a single thermal cycle.
• Three-electrode oil cup compliant with GB/T 5654–2007: Eliminates stray capacitance and surface leakage effects through guarded electrode geometry; nominal empty-cell capacitance: 60 ±5 pF; empty-cell tan δ < 5×10⁻⁵.
• PID-controlled induction heating system: Enables rapid, uniform oil temperature stabilization without physical contact between heater and cup — reducing thermal gradient error and improving repeatability.
• Digital measurement architecture: Full 24-bit ADC resolution, auto-ranging, and real-time correction for ambient temperature and humidity drift.
• Integrated SF₆-filled reference capacitor: Stable capacitance and negligible tan δ over time and environmental variation, preserving long-term calibration integrity.
• 7-inch capacitive touchscreen with localized Chinese GUI: Context-sensitive prompts, step-by-step workflow guidance, and intuitive parameter entry — no specialized operator training required.
• Safety interlocks: Automatic high-voltage cutoff upon oil cup lid opening; short-circuit detection between high- and low-potential electrodes; mandatory grounding verification prior to test initiation.

Sample Compatibility & Compliance

The GDAT-C1 is validated for use with mineral insulating oils (e.g., naphthenic and paraffinic transformer oils), synthetic esters, and silicone-based dielectric fluids meeting IEC 60296 or ASTM D3487 specifications. Its three-electrode cell design accommodates 40 mL sample volume and supports both routine maintenance testing and diagnostic assessment per DL/T 596 and IEEE C57.106. The instrument satisfies technical requirements for GLP-compliant laboratories: all test parameters (voltage, temperature, duration, date/time stamp) are embedded in each stored record; audit trail functionality is enabled via internal RTC and non-volatile memory. While not FDA 21 CFR Part 11 certified out-of-the-box, raw data export (CSV) and manual record retention support traceability in regulated environments requiring ISO/IEC 17025 documentation.

Software & Data Management

All measurement logic, calibration routines, and user interaction are implemented in embedded firmware — no external PC dependency. Test results include: capacitance (5–200 pF, 0.01 pF resolution), ε_r (1.000–30.000, ±1% reading), tan δ (1×10⁻⁵–100, ±(1% reading + 0.0001)), and ρ_v (2.5 MΩ·m to 20 TΩ·m, ±10% reading). Each record stores ambient temperature, oil temperature, applied voltage, measurement duration, and operator ID (manually entered). Up to 100 tests are retained with automatic timestamping; data can be printed via built-in thermal printer or exported via USB interface (CSV format). The “empty cup calibration” function verifies electrode cleanliness and mechanical assembly integrity prior to sample introduction — critical for achieving ≤5% measurement uncertainty in accredited labs.

Applications

• Condition monitoring of power transformer insulation oil in substation maintenance programs.
• Quality assurance during oil reclamation, regeneration, or blending processes.
• Acceptance testing of new insulating oils per manufacturer specifications and grid operator standards (e.g., State Grid Corporation of China Q/GDW 11212).
• Research and development of next-generation biodegradable dielectric fluids.
• Root-cause analysis of insulation degradation: elevated tan δ indicates polar contaminant accumulation; reduced ρ_v suggests moisture ingress or oxidation byproducts.

FAQ

What standards does the GDAT-C1 comply with?

It is designed and verified per GB/T 5654–2007, with functional alignment to IEC 60247 and ASTM D924 for dielectric loss and resistivity measurements.

Is the oil cup cleaning procedure standardized?

Yes — the manual provides two protocols: full cleaning (per GB/T 5654 Annex B) for acceptance testing, and simplified cleaning for routine diagnostics, including oil-rinsing procedures between consecutive samples.

Can test data be exported for LIMS integration?

Yes — measurement records are exportable as CSV files via USB flash drive; timestamps, operator IDs, and environmental metadata are included.

What safety certifications does the instrument carry?

It meets GB 4793.1 (equivalent to IEC 61010-1) for electrical safety and includes redundant hardware interlocks for high-voltage and thermal protection.

Is temperature calibration traceable to national standards?

The integrated Pt100 sensor is factory-calibrated against NIM-traceable references; users may perform field verification using certified dry-block calibrators (–10 to 150 °C range).