Thermolyne NCAT Asphalt Content Furnace Manual

The Thermolyne NCAT Asphalt Content Furnace is a specialized laboratory instrument designed for determining asphalt content in hot mix asphalt (HMA) samples using the ignition method. This furnace features digital temperature control, automatic test sequencing, built-in calibration, safety interlocks, and compliance with AASHTO T 308 and ASTM D 6307 standards. Below are key sections for safety, operation, calibration, maintenance, and troubleshooting.

Features at a Glance

Key components: Digital temperature controller, ceramic combustion chamber, sample basket assembly, exhaust system, safety door interlock, calibration software.

Installation Requirements

Unpack and inspect all components. Ensure proper ventilation and electrical supply.

1. Location: Install in well-ventilated area with minimum 6 inches clearance on all sides.
2. Electrical: Connect to dedicated 240V AC, 30A circuit with proper grounding.
3. Ventilation: Connect exhaust duct to building ventilation system.
4. Leveling: Place on stable, level surface using adjustable feet.

WARNING! Furnace operates at high temperatures; ensure proper clearance from combustible materials. Use heat-resistant gloves when handling hot components.

Initial Setup

Power on furnace; perform initial calibration and safety checks.

1. Power connection: Verify proper voltage and grounding.
2. Exhaust system: Ensure proper airflow and connection.
3. Controller setup: Set date, time, and unit preferences.
4. Initial burn-off: Run empty chamber at 538°C for 30 minutes to remove manufacturing residues.
5. Calibration: Perform initial calibration with known asphalt content samples.

CAUTION! Always wear appropriate PPE: heat-resistant gloves, safety glasses, and lab coat during operation.

Technical Specifications

• Temperature Range: Ambient to 600°C (1112°F)
• Temperature Control: ±2°C accuracy
• Chamber Volume: 0.085 m³ (3.0 ft³)
• Sample Capacity: 4000g maximum
• Power Requirements: 240V AC, 50/60Hz, 30A
• Dimensions: 76cm W × 76cm D × 91cm H (30" × 30" × 36")
• Weight: 136 kg (300 lbs)
• Display: Backlit LCD with touchpad controls
• Calibration Memory: 10 calibration factors
• Standards Compliance: AASHTO T 308, ASTM D 6307

Controls and Operation

Front Panel: POWER switch, DOOR OPEN/CLOSE, EMERGENCY STOP, temperature display, function keys.

Controller Functions: TEMP SET, TIME SET, CALIBRATION, TEST START/STOP, MANUAL MODE.

Operation Modes: STANDARD TEST - automatic ignition test; CALIBRATION - establish correction factors; MANUAL - user-controlled temperature and time. Safety Features: Door interlock prevents operation when open; over-temperature protection; emergency stop button.

Sample Preparation

Proper sample preparation is critical for accurate results.

1. Obtain representative HMA sample (1500-4000g).
2. Dry sample to constant weight if necessary.
3. Weigh sample to nearest 0.1g (tare basket weight).
4. Record initial mass as W1.
5. Ensure sample is evenly distributed in basket.

Tip: Samples should be at room temperature before testing to prevent thermal shock.

Testing Procedure

Standard test procedure for asphalt content determination.

1. Load sample: Place prepared sample basket into chamber.
2. Close door: Ensure proper seal and interlock engagement.
3. Select test: Choose STANDARD TEST from menu.
4. Start test: Press START - furnace will automatically ramp to 538°C.
5. Monitor: Watch for stable mass indication (test complete).
6. Record results: Final mass (W2) and calculated asphalt content.
7. Calculate: Asphalt Content (%) = [(W1 - W2) / W1] × 100 + Calibration Factor
8. Cool down: Allow chamber to cool below 100°C before removing sample.

WARNING! Do not open door during test. Chamber temperatures exceed 500°C and can cause severe burns.

Calibration

Regular calibration ensures accurate results. Perform when changing aggregate source or every 6 months.

1. Select CALIBRATION mode from main menu.
2. Enter known asphalt content of calibration sample.
3. Run test following standard procedure.
4. System calculates and stores correction factor.
5. Verify accuracy with second calibration sample.

Calibration factors are stored in non-volatile memory and applied automatically to test results.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

Daily: Wipe exterior with damp cloth; check exhaust airflow. Weekly: Clean combustion chamber; inspect heating elements. Monthly: Check door seal; verify calibration; inspect electrical connections.

CAUTION! Always disconnect power before performing maintenance. Allow furnace to cool completely before cleaning.

Safety Information

FCC Part 15: Class A digital device; may cause interference in residential areas. UL listed; CSA certified. Always wear appropriate PPE. Ensure proper ventilation to prevent fume accumulation. Keep flammable materials away from furnace. Emergency procedures: Use EMERGENCY STOP button; have Class C fire extinguisher available.

Troubleshooting

Reset: Power cycle unit; perform system reset from maintenance menu if available.

Service: Contact Thermolyne Technical Support: 1-800-553-0039; www.thermolyne.com