The Model BBV series instrument is a versatile beam bending viscometer system that can determine;

1. annealing & strain point temperatures of a solid glass beam according to the ASTM C-598 procedure or,
2. the temperatures for a range of viscosities of a solid glass beam according to the ASTM C-1350m procedure.

The annealing and strain points of a glass are widely used production control parameters. Changes in the annealing and strain point temperatures are indications of chemistry changes. If forming a fiber is not desired, is impractical, or impossible, annealing and strain point temperatures can still be determined using cut or machined rods or bars in a beam bending viscometer according to ASTM C-598.

The annealing point temperature is the temperature at which a 2-point supported horizontal bar or rod with a uniform cross section deflects under an applied mid-point load at a prescribed calculated rate while cooling in a special furnace at the rate of 4°C per minute. The strain point temperature is determined by extrapolation of the annealing point data and is the temperature at which the mid point deflection rate is 0.0316 times the deflection rate observed at the annealing point.

These tests are performed with an LVDT extensometer system that is manufactured by Orton. The Model BBV Series has been designed to automatically monitor the deflection of the sample beam and calculate the annealing and strain points according to the ASTM C-598 method, or calculate the temperature for a range of viscosities according to the ASTM C-1350M method.

Model BBV-1200