PLC Controlled Loading Devices

PLC controlled loading devices are used in applications where constant load tests (ASTM G44 / ASTM G47 / NACE TM0177 Method A) or step-wise constant load or constant strain tests (ASTM F1624) are performed. This loading device is less versatile than the PC operated loading device but it is more affordable.

The loading device has an identical gear box and a load cell with the PC controlled loading device. The operation is controlled using a touch panel instrumented PLC that operates a gear box DC motor based on the load cell signal.

These instruments are often used with ASTM G44 - 21 "Standard Practice for Exposure of Metals and Alloys by Alternate Immersion in Neutral 3.5 % Sodium Chloride Solution". The specimens will be periodically immersed in salt water with "10 minutes wet / 50 minutes dry" - cycle. A constant load will be maintained continuously. A PLC with a HMI touchpanel will be used for the loading device and the wetting device operation.