The Orton Model SP-1A-DAS 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. Changes in the softening point temperature can be used as an indication of changes in batch chemistry from raw material changes or batching errors.

Automatic Softening Point Determination
It takes 5 minutes to measure the Littleton Softening Point of a glass fiber. It's simple. After the test fiber is pulled to meet the ASTM C-338 specified dimensions, the operator places the fiber into the preheated furnace, aligns the fiber in the laser path, pushes the START button, and walks away. The system does the rest. The operator is free to perform other tasks. Five minutes later, the operator returns and reads the Littleton Softening Point Temperature. It's that easy. The SP-1A-DAS automatically calculates the rate of elongation and displays the softening point temperature which eliminates operator differences, judgements, and errors. The Model SP-1A-DAS is a FAST, EASY, ACCURATE, RELIABLE, and REPRODUCIBLE method for QC checks on batch chemistry changes.

Description
This system is comprised of the ASTM specified furnace to heat the fiber; the Orton PID controller to operate the furnace according to the ASTM C338 thermal cycle, laser system to monitor the elongation of the test fiber, the Orton on board computer with internal logic to determine the softening point, digital display panel for displaying the softening point temperature, and software for an independent computer (provided by the purchaser).

Operation
The system is initially heated to an equilibrium soak temperature, and waits for the next test. After the fiber is inserted and aligned, and the START button pushed, the Orton controller heats the furnace at 5ºC per minute and captures the temperature and laser signals. As the temperature increases and the fiber elongates, the laser system follows the tip of the elongating fiber and continuously sends its signal to the on board computer. The on board computer calculates the elongation rate as a function of time, and concludes the test once the elongation rate exceeds 1.05 millimeters per minute. The on board computer selects the temperature at which the elongation rate is 1.00 millimeters per minute and displays that softening point temperature until the system is reset. The furnace automatically cools to the soak temperature in about 15 minutes, and is ready for the next test. The on board computer can store data for up to 10 tests.

The system is initially heated to an equilibrium soak temperature, and waits for the next test. After the fiber is inserted and aligned, and the START button pushed, the Orton controller heats the furnace at 5ºC per minute and captures the temperature and laser signals. As the temperature increases and the fiber elongates, the laser system follows the tip of the elongating fiber and continuously sends its signal to the on board computer. The on board computer calculates the elongation rate as a function of time, and concludes the test once the elongation rate exceeds 1.05 millimeters per minute. The on board computer selects the temperature at which the elongation rate is 1.00 millimeters per minute and displays that softening point temperature until the system is reset. The furnace automatically cools to the soak temperature in about 15 minutes, and is ready for the next test. The on board computer can store data for up to 10 tests.

If desired, a separate, independent computer system (not included) can be connected to the Orton controller console via a RS232 port. The independent computer, using Orton supplied software, can display and store the fiber elongation rate, time, and temperature. The data is stored in a text file on the hard drive for later independent review, analysis, or permanent storage.

*Descriptions & specifications are subject to change without notice

Manual Littleton Softening Point Measurement Instruments
Model SP-1A System
This is the original system to manually perform the measurements. The temperature of the ASTM specified furnace is controlled manually with a Variac. Using a telemicroscope mounted on an independent stand, the operator manually observes the fiber elongation against an independently supported scale, and manually records that elongation along with the temperature. The operator manually plots the data points and picks the softening point temperature from the graph.

Model SP-1A-DM System
This is a modified version of the original SP-1A design. It uses a digital micrometer on the telemicroscope to make the elongation measurements easier and more accurate.