Meeting AMS2750 Class 1 Temperature Uniformity Standards with SH Scientific

In the aerospace industry, precision is a strict regulatory requirement. The standard that governs the temperature management of heat treatment equipment in this sector is AMS2750. For facilities processing mission-critical aerospace materials, managing and documenting your thermal environment is essential.

At Lab and Furnace, we partner with manufacturers who engineer equipment capable of meeting these extreme tolerances. Recent Temperature Uniformity Survey (TUS) data confirms that specific SH Scientific custom furnaces deliver the thermal stability required to satisfy AMS2750 Class 1 uniformity parameters.

(Note: While the temperature uniformity of these furnaces satisfies Class 1 requirements, full AMS2750 compliance involves additional facility-level protocols, including ongoing sensor calibration and rigorous documentation.)

Understanding AMS2750 Core Requirements

To maintain strict temperature control, the AMS2750 standard outlines several critical management protocols. Two of the most vital are:

1. TUS (Temperature Uniformity Survey): This requires the user to periodically measure the temperature consistency across the entire working zone of the furnace. Typically, this involves placing sensors at nine distinct points within the chamber to map the thermal environment.
2. SAT (System Accuracy Test): This is a periodic verification of the furnace’s sensor accuracy. It is conducted by the user by comparing the readings of the furnace’s built-in control sensor against a highly calibrated reference sensor to account for any drift.

Based on these measurements, the furnace’s thermal environment is categorized into distinct classes:

• Class 1: ± 3°C
• Class 2: ± 6°C
• Class 3: ± 8°C
• Class 4: ± 10°C
• Class 5: ± 14°C

SH Scientific Temperature Uniformity Test Results

To validate their engineering, SH Scientific conducted thorough temperature uniformity tests using Process Temperature Control Rings (PTCR) across multiple points within their furnace chambers. The data below outlines the thermal variance for various muffle and tube furnace models.

Aerospace Custom Muffle Furnaces (Class 1 Uniformity)

SH-FU-27MG-OM Custom model for Aerospace AMS2750 Class 1 (1200°C Muffle Furnace, 300x300x300mm chamber)

• Test 1 (600°C Target): Ramp up rate 5°C/min, hold for 2 hours. The average temperature was 650.6°C. Uniformity measured at ± 1.6°C (0.5%), satisfying Class 1.
• Test 2 (700°C Target): Ramp up rate 5°C/min, hold for 2 hours. The average temperature was 748.4°C. Uniformity measured at + 1.4°C (0.4%), satisfying Class 1.

SH-FU-70MGV-OM

Large Scale Vacuum Muffle Furnace (1200°C, 415x415x415mm chamber)

• Test: Multi-stage ramp up to 850°C, hold for 1 hour, followed by a controlled cooling rate to 500°C.
• Result: The average temperature across measured points was 847.51°C. Uniformity measured at ± 1.95°C (0.5%), satisfying Class 1.

Standard High-Temperature Muffle Furnaces

SH-FU-27MGQ
1200°C Quartz Chamber Muffle Furnace (300x300x300mm chamber)

• Test: Ramp up rate 5°C/min to 800°C, hold for 2 hours.
• Result: The average temperature was 834°C. Uniformity measured at ± 3°C (0.7%).

SH-FU-11MS
1900°C Muffle Furnace (200 W x 270 D x 200 H mm chamber)

• Test: Ramp up rate 10°C/min up to 1600°C, hold for 2 hours.
• Result: The average temperature was 1644.4°C. Uniformity measured at an exceptional ± 0.6°C (0.1%).

Tube Furnaces

SH-FU-100LTG (3 Zone)
1200°C 3-zone tube furnace (OD 100mm tube & 600mm hot zone)

• Test 1: Ramp up rate 5°C/min up to 750°C, hold for 2 hours. The average temperature was 815.35°C. Uniformity measured at ± 7.35°C (1.8%) within a 400mm center area.
• Test 2: Ramp up rate 5°C/min up to 1000°C, hold for 2 hours. The average temperature was 1065.00°C. Uniformity measured at ± 7.00°C (1.3%) within a 400mm center area.

SH-FU-80LTG
1200°C tube furnace (OD 80mm tube & 600mm hot zone)

• Test: Ramp up rate 5°C/min up to 750°C, hold for 2 hours.
• Result: The average temperature was 827.9°C. Uniformity measured at ± 6.1°C (1.5%) within a 200mm center area.

SH-FU-30STG
1200°C mini tube furnace (OD 30mm tube & 150mm hot zone)

• Test: Ramp up rate 5°C/min up to 750°C, hold for 2 hours.
• Result: The average temperature was 809.8°C. Uniformity measured at ± 9.8°C (1.2%) within a 100mm center area.

The Lab and Furnace Approach

When you are processing materials where failure is not an option, you need equipment capable of maintaining absolute thermal consistency. The TUS data demonstrates that SH Scientific’s specialized aerospace models provide the thermal uniformity necessary to satisfy AMS2750 Class 1 parameters.

By delivering a baseline variance of ± 3°C or better, these furnaces provide operators with the stable foundation needed to successfully implement a fully compliant heat treatment program.

For more information on configuring an SH Scientific furnace for your precision applications, explore our catalog or contact the technical sales team at labandfurnace.com.