Littleton Softening Point
The softening point of a glass is the most widely used production control parameter.
Changes in the softening point temperature are indications of chemistry changes. According to ASTM C-338 the softening point temperature is the temperature at which a uniform fiber of glass (0.65 mm in diameter x 23.5 cm long) elongates under its own weight at a rate of 1.0 millimeters per minute when the upper 10 cm of its length is heated in a special furnace at the rate of 5°C per minute. This test is performed in a laser optic extensometer system that is manufactured by Orton. The Orton Model LSP Series has been designed to automatically monitor the elongation of the sample fiber and calculate the Littleton softening point according to the ASTM C-338 method.
(Note: If forming a fiber is not desired, is impractical, or impossible, the softening point temperature RANGE can still be determined by the Parallel Plate Viscometer method, ASTM C-1351M.)
Model LSP-1000
General
A laboratory, bench-top, fiber elongation system for automatically determining Littleton softening point of a glass fiber below 1000C.
Operated according to ASTM C-338 Method or modified version of this procedure.
Includes
- Bench top instrument console
- 1000°C furnace
- programmable process controller
- laser micrometer and controller
- type “S” thermocouple
- computer software
- accessories and instruction manual. (Computer not included.)
Specifications
| Model | LSP-1000 |
| Warranty | 12 Months |
| Accuracy | +/-2C |
| Atmosphere | Air |
| Temperature Range | RT to 1000°C |
| Furnace Core | Inconel |
| Heated Length | 3.25 inches (83 mm) |
| Laser Type | FDA Class II / IEC Class 1 |
| Laser Micrometer Range | 0 – 35 mm |
| Sample Load | none |
| Thermocouple | Type “S |
| Sample Size | 235 mm long x 0.65 mm diameter |
| Power Control | 4-20 ma |
| Power Requirements | 120vac/10amp or 240vac/5amp, 50 or 60 Hz |
| Temperature Control | Honeywell UDC 3200 Process controller |
| Computer Interface Software | Included |
| SRM Calibration samples | Optional |
| Bench-top Footprint (stand) Length x Depth x Height | 10 x 10 x 15 (25 x 25 x 38 mm) |
| Bench-top Footprint (controller) Length x Depth x Height | 18 x 12 x 5 (46 x 31 x 13 cm) |