Orton Model SP-4A Series Molten Glass Viscometers

are designed to measure the viscosities of glasses at various temperatures for ASTM C-965 Procedure A and ISO 7884/2 testing. The Model SP-4A is used to measure viscosities at specific temperarures in order to generate a curve of the viscoelastic behavior of molten glass, as shown in the graph to the right.

Model SP-4A-CC

To make testing cost effective, Orton designs the system to accommodate your platinum crucible size. The systems in the photographs are examples of units that were designed specifically for the customer's sample crucible size requirements. The photo to the left is a 1,500°C, laboratory bench top system using a platinum crucible approximately 74 mm (2.9”) tall with a top OD of 68 mm (2.7”) which contains approximately 300 grams of glass. The photo to the right is a 1,500°C, glove box system using a platinum crucible approximately 64 mm (2.50”) tall by 22 mm (0.865”) OD, which contains less than approximately 10 grams of glass.

Model SP-4A-GB

The Model SP-4A System includes vertical tube furnace (molybdenum disilicide, platinum, or silicon carbide heating elements), a type “S” furnace control thermocouple, a temperature control system with a multi-segment user programmable PID controller, stepdown transformer (if required), a crucible support pedestal, a type “S” sample thermocouple, a Brookfield viscometer, and component support structure.

The crucible is loaded into the system in one of three ways. First, the crucible is placed on a fixed pedestal support, and the furnace is lowered over the crucible. Second, the crucible is placed on the moveable support pedistal, and the pedestal is raised into the fixed position furnace. And third, the crucible is manually lowered into the fixed position furnace and rests on the fixed position pedestal support. The pedestal or furnace movements can be manual or motorized.

It is necessary to lower and raise the spindle into and out of the molten glass in the crucible. The viscometer is supported above the furnace, and is normally raised and lowered manually, but can be motorized.

The entire system is designed around the purchaser’s crucible size, range of viscosities, component movement method, and budgetary constraints.

The crucible and spindle can be supplied by Orton, however, since most glass companies have access to lower cost platinum, most users provide their own crucibles and spindles.

*Descriptions and specifications are subject to change without notice.