Cannon TE-BBR, Инструкция по эксплуатации, Страница: 13 / 92

2 TE-BBR Instruction and Operation Manual
Control Unit
The Control Unit is the base for the Bending Beam Rheometer. It contains the electronic
components required to condition the signals from the Linear Variable Differential Transducer
(LVDT), load cell, and temperature probe, and to communicate with the host computer via the serial
port. Also included in the Control Unit are the relays, switches, and solenoid valves that control the
introduction of pressurized gas to the chamber below the air bearing. The Control Unit contains
pressure regulators and gages for operation of the pneumatic system. The low temperature bath is
also an integral part of the Control Unit and is surrounded by thermoelectric modules to permit solid
state cooling. Refer to Figure 2.
Figure 2: Front of Control Unit
Load Frame
The Load Frame rests on top of the Control Unit. The lower section is immersed in the alcohol bath.
The Load Frame consists of a frame with the LVDT at the uppermost section, a shaft with an
attached platform for holding weights, an air bearing through which the shaft passes, a load cell
integral with the shaft below the bearing, and at the lower end is the support for the beam. The
frame also contains several filters for the compressed gas and an illumination system to assist the
operator in the placement of the beams on the supports.
An air chamber directly below the air bearing provides a force that counterbalances much of the
load that would be applied to the specimen from the weight of the shaft. The pressure in the air
chamber, or cylinder, can be adjusted - any desired load can be applied to the specimen, up to the
maximum or the full weight of the shaft. Refer to Figure 3.