Dickey-john GAC2500C High-Precision Grain Moisture Analyzer
| Brand | Dickey-john |
|---|---|
| Origin | USA |
| Model | GAC2500C |
| Instrument Type | Benchtop |
| Sample Types | Grains, oilseeds, grass seeds, vegetable seeds, legumes, walnuts, almonds, coffee beans |
| Analysis Time | 10 s |
| Sample Weight | 250 g |
| Scan Speed | 10 s |
| Weight | 15 kg |
| Measurement Principle | 149 MHz Radio Frequency (RF) Dielectric Sensing |
| Compliance | NTEP Certified (National Type Evaluation Program), ASTM D4940, ISO 712 |
Overview
The Dickey-john GAC2500C High-Precision Grain Moisture Analyzer is a benchtop radio frequency (RF) dielectric moisture measurement system engineered for rapid, non-destructive, and repeatable quantification of moisture content in bulk agricultural commodities. Operating at a stable 149 MHz RF frequency, the instrument measures the dielectric permittivity and conductance of grain samples—parameters directly correlated with water content—via calibrated electromagnetic field interaction within a precisely defined sample cavity. Unlike near-infrared (NIR) or capacitance-based systems, the 149 MHz platform minimizes interference from temperature fluctuations, kernel density variations, and surface moisture, delivering metrological consistency across heterogeneous lots. The GAC2500C meets National Type Evaluation Program (NTEP) Class III certification requirements for commercial grain trade applications and complies with ASTM D4940 (Standard Test Method for Electrical Conductivity of Water) and ISO 712 (Cereals and cereal products — Determination of moisture content — Reference method), ensuring traceability to national standards.
Key Features
- 149 MHz RF dielectric sensing architecture optimized for high reproducibility across diverse commodity types—including corn, wheat, soybeans, barley, oats, sorghum, flaxseed, sunflower seed, and specialty crops such as walnuts, almonds, and green coffee beans.
- Integrated infrared temperature sensor enabling real-time thermal compensation during analysis, eliminating manual correction and reducing operator-induced variability.
- Touchscreen interface with intuitive navigation, multi-language support (English, Spanish, French, Portuguese), and context-sensitive help menus for rapid operator onboarding.
- Onboard calibration management supporting up to 200 user-defined commodity-specific calibrations, each with editable slope/intercept parameters, offset values, and temperature coefficients.
- Rugged cast-aluminum chassis with vibration-damped sample chamber; designed for continuous operation in grain elevators, feed mills, research laboratories, and quality control environments.
- Automatic moisture drift compensation algorithm that adjusts for ambient humidity and electronic thermal drift over extended operational cycles.
Sample Compatibility & Compliance
The GAC2500C accommodates standard 250 g sample volumes across a broad spectrum of particulate agricultural materials. Its RF cavity geometry and signal processing firmware are validated for uniform response in grains with varying kernel size, shape, and density—from fine grass seeds (25 mm). Calibration models are developed per AOAC Official Method 992.03 (Moisture in Cereal Grains by RF Dielectric Method) and verified against gravimetric reference methods (AOAC 950.46). All factory calibrations are documented under GLP-compliant procedures and include uncertainty budgets traceable to NIST SRM 1889b (Moisture in Corn). The unit carries full NTEP Certificate No. 19-009 for legal-for-trade use in the United States and Canada.
Software & Data Management
Data acquisition, storage, and reporting are managed via the embedded GACLink™ firmware v4.2. Each analysis generates a timestamped record containing moisture % w.b., sample ID, calibration ID, ambient temperature, RF signal amplitude, and diagnostic flags. Up to 10,000 results are retained locally with automatic overwrite protection. Export options include CSV via USB 2.0 port or Ethernet (optional), compatible with LIMS integration using standard TCP/IP protocols. Audit trail functionality logs all calibration changes, user logins, and firmware updates in accordance with FDA 21 CFR Part 11 requirements when paired with optional GACSecure™ authentication module.
Applications
- Real-time moisture verification prior to grain drying, storage, or blending operations in elevator and cooperative facilities.
- Quality assurance screening of incoming raw materials in animal feed and flour milling plants.
- Research-grade moisture profiling for agronomy trials evaluating drought tolerance or post-harvest handling protocols.
- Regulatory compliance testing for USDA-GIPSA, CFIA, and EU Regulation (EC) No 882/2004 on official controls.
- Contractual arbitration where NTEP-certified moisture data serves as binding basis for price adjustments.
FAQ
What is the measurement principle used in the GAC2500C?
It employs 149 MHz radio frequency dielectric sensing, measuring the complex impedance of grain samples to determine moisture content based on established dielectric-moisture relationships.
Does the GAC2500C require daily recalibration?
No—factory calibrations remain stable for ≥6 months under normal operating conditions; verification against reference standards is recommended weekly per ISO/IEC 17025 guidelines.
Can it measure moisture in roasted or ground coffee beans?
No—the instrument is validated only for whole, unprocessed green coffee beans; roasting alters dielectric properties and invalidates calibration.
Is the unit compliant with FDA 21 CFR Part 11 for electronic records?
Yes, when configured with GACSecure™ user authentication and audit trail logging, it satisfies electronic signature and record retention requirements.
What environmental conditions affect measurement accuracy?
Ambient temperature extremes (40°C) and relative humidity >85% may impact repeatability; the built-in IR temperature sensor mitigates thermal drift but does not compensate for condensation or static charge buildup.
