Automatic Test Weight Lift & Storage Mechanism

More and more weigh feeders are being used in conjunction with statistical process control where performance records are routinely generated and delivered with the product as required by a customer’s quality assurance program. Such a record should contain a “validation of scale calibration” step to be truly meaningful as a quality assurance tool. Thayer’s automatic test weight mechanism provides a means for automatically applying a known test weight and going through a calibration sequence on computer or push-button demand to check scale calibration. A “foolproof” self-checking software algorithm in the feeder control instrumentation prevents erroneous calibration.

CALIBRATION is fast, accurate and reliable

The Thayer Scale test weight calibration method has proven accurate and reliable over decades of in-plant use. Unlike material sampling, it is always clean, fast and safe. Unlike electronic signal stimulation scale loading, it actually tests the performance of critical electro-mechanical components. The Thayer Automated Test Weight Placement Assembly now makes calibration even easier and more exact:

Thayer ATWL Features

• Auto Zero Calibration.
• Auto span calibration with test load.
• Auto calibration and zero and span.
• Auto adjustment of zero and span errors.
• History of past calibration results stored in instrument for trending and determination of required calibration interval.

Thayer ATWL Benefits

• Minimal downtime for calibration checks.
• When automatic calibration check is carried out via a remote computer or PC, human intervention is not required. Eliminates operator error and institutionalizes calibration checks at regular time intervals for compliance with QA programs.
• Eliminates risk of operator injury from lifting and placing test weights.
• Mechanically exercises scale. Actually verifies load cell operation, unlike an electronic shunt calibration.

Competitors Method of Calibration

• Electronic signal Simulation: Fast, but does not apply load to scale.
• Test weight: loads scale mechanism, difficult to use, storage can be a problem, time consuming, hard to handle for large feeders.
• Material Test: Time consuming, most comprehensive, but accuracy of calibration is subject to accuracy of sampling methods and accuracy of scale used to weigh samples.