North Guang BEST-212 Volume and Surface Resistivity Tester
| Brand | North Guang Precision Instrument |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | Manufacturer |
| Product Origin | Domestic (China) |
| Model | BEST-212 |
| Price | USD 1,150 (FOB Beijing) |
| Resistance Range | 1×10⁴ Ω to 1×10¹⁸ Ω |
| Current Measurement Range | 2×10⁻⁴ A to 1×10⁻¹⁶ A |
| Test Voltages | DC 10 V, 50 V, 100 V, 250 V, 500 V, 1000 V (±10%) |
| Display | Full-digit LCD |
| Accuracy | ±1% (10⁴–10⁹ Ω), ±5% + 2 digits (10¹⁰–10¹² Ω), ±10% + 5 digits (≥10¹³ Ω) |
| Operating Temperature | −10 °C to +50 °C |
| Relative Humidity | <90% RH |
| Power Supply | AC 220 V, 50 Hz, ~10 W |
| Dimensions | 300 mm × 280 mm × 150 mm |
| Weight | ~3.0 kg |
Overview
The North Guang BEST-212 Volume and Surface Resistivity Tester is a precision electrometric instrument engineered for high-accuracy measurement of extremely high resistance values and ultra-low direct current (DC) in solid insulating materials. Based on the fundamental principle of Ohm’s Law (R = V/I), the instrument simultaneously acquires both applied test voltage and resulting current through a high-stability feedback-controlled source and low-noise current amplifier architecture. Unlike conventional analog or single-parameter high-resistance meters, the BEST-212 employs dual-sensing circuitry—measuring voltage across and current through the sample in real time—and performs real-time digital division via embedded large-scale integrated circuits (LSI). This eliminates nonlinearity inherent in traditional meter movements and significantly reduces sensitivity to source drift, contact resistance, and environmental fluctuations. The result is stable, reproducible resistivity data across 14 decades of resistance (10⁴–10¹⁸ Ω) and 12 decades of current (10⁻⁴–10⁻¹⁶ A), meeting core metrological requirements for R&D laboratories, quality control departments, and compliance testing facilities evaluating electrostatic dissipation (ESD) safety and dielectric integrity.
Key Features
- Simultaneous digital display of resistance value (Ω) and measured current (A) on a full-digit LCD screen—enabling immediate correlation between material response and excitation conditions
- Six selectable DC test voltages (10 V, 50 V, 100 V, 250 V, 500 V, 1000 V) with ±10% tolerance, supporting standardized test protocols per ASTM D257, IEC 60093, and GB/T 1410
- Auto-ranging resistance measurement from 1×10⁴ Ω to 1×10¹⁸ Ω across ten calibrated decades; current measurement from 2×10⁻⁴ A to 1×10⁻¹⁶ A
- High-precision current sensing circuitry optimized for sub-picoampere resolution, suitable for dark current characterization in photodetectors and leakage analysis in semiconductor packaging
- Compact benchtop design (300 × 280 × 150 mm, ~3.0 kg) with low power consumption (~10 W), facilitating integration into controlled lab environments without thermal load concerns
- Internal shielding and dedicated guard terminal minimize stray capacitance and electromagnetic interference—critical for repeatable surface resistivity measurements on low-conductivity polymers and coatings
Sample Compatibility & Compliance
The BEST-212 supports both two-electrode and three-electrode configurations as defined in GB/T 1410 (equivalent to IEC 60093) for unambiguous separation of volume and surface conduction pathways. For surface resistivity (ρs) determination, the instrument connects the high-voltage output to the guard ring electrode, the current input to the central electrode, and the guard/shield terminal to the bottom plate. For volume resistivity (ρv) measurement, the high-voltage output is routed to the bottom plate, current input to the central electrode, and guard to the ring electrode. This configuration ensures accurate field confinement and eliminates edge effects in sheet-type specimens (e.g., ESD flooring tiles, antistatic mats, polymer films, and elastomeric gaskets). The instrument complies with functional safety requirements for Class II electrical equipment and meets EMC immunity standards per IEC 61326-1 for laboratory use. While not certified to ISO/IEC 17025 calibration traceability out-of-the-box, its documented accuracy profile supports in-house verification against NIST-traceable reference resistors and picoammeters.
Software & Data Management
The BEST-212 operates as a standalone instrument with no proprietary software dependency—designed for operational simplicity and long-term maintenance predictability. All measurements are displayed directly on the front-panel LCD without scaling factors or manual coefficient multiplication, reducing operator error during high-resistance evaluation. For traceable recordkeeping, users may manually log readings alongside test parameters (voltage, electrode geometry, ambient T/RH) in accordance with GLP documentation practices. When integrated into automated test systems, the instrument’s analog output (0–2 V proportional to log₁₀(R)) and RS-232 interface (optional) enable external acquisition by LabVIEW, Python-based DAQ platforms, or LIMS-compatible controllers. Audit trails, electronic signatures, and 21 CFR Part 11 compliance require third-party middleware—not built-in—but the deterministic analog output and stable digital readout ensure compatibility with validated data capture workflows.
Applications
- Quality assurance of ESD-control products: footwear soles, conductive flooring, static-dissipative workbenches, and polymer enclosures per ANSI/ESD S20.20
- Volume and surface resistivity mapping of insulating plastics, rubber compounds, ceramic substrates, and composite laminates used in aerospace and medical device housings
- Material science research on charge transport mechanisms in dielectrics, ferroelectrics, and 2D layered materials under controlled bias conditions
- Leakage current profiling of optoelectronic components—including photodiodes, image sensors, and OLED substrates—where dark current below 100 fA must be quantified reliably
- Validation of cleaning efficacy and contamination control in cleanroom environments via surface resistivity shifts after solvent wipe tests
FAQ
What standards does the BEST-212 support for resistivity testing?
It fully supports GB/T 1410 (identical to IEC 60093) and is compatible with ASTM D257 test methodologies for volume and surface resistivity of solid electrical insulating materials.
Can the instrument measure both volume and surface resistivity on the same sample?
Yes—using the included three-electrode fixture and proper wiring per GB/T 1410, users can sequentially determine ρv and ρs without reconfiguring the specimen.
Is calibration required before first use?
The unit ships with factory calibration; however, users should perform a zero-check and open-circuit verification prior to critical measurements, especially after transportation or temperature cycling.
How does the instrument handle noise during ultra-low-current measurement?
It integrates guarded inputs, low-leakage triaxial cabling support, and internal electrostatic shielding—reducing noise floor to ≤1 fA RMS in optimal lab conditions (≤40% RH, grounded bench, Faraday cage optional).
Does the BEST-212 meet FDA or ISO 13485 requirements for medical device testing?
While not pre-certified, its documented accuracy, stability, and traceable measurement principle make it suitable for inclusion in IQ/OQ/PQ protocols when validated against reference standards per ISO 13485 clause 7.6.
