Introducing New Flexible Calibration Concepts

Step Calibration

Step Calibration automates a field technique used when the capacity of a scale is much larger than the available test mass. The substitution method of calibration uses a known test mass to calibrate a small portion of the scale’s weighing capacity. After calibration of this portion is established, the test load is removed, and a substitute material is placed inside the vessel or hopper to a point near the calibrated load. The test mass is then added to this value, and a new calibration point is established. The process is repeated until the last calibration point is near the scale’s capacity. In the past, this process required that the scale technician manually calculate each successive calibration value and enter the appropriate figures into the terminal, making it prone to entry or computational error. With METTLER TOLEDO’s Step Calibration the procedure is automated, taking the technician through each step, and eliminating the need to do the math or enter values.

CalFree™

CalFree™ is a combination of a field calibration technique and factory controlled quality assurance processes. During the production of a load cell, the actual gain of the cell is measured and recorded. In addition, each terminal’s analog measurement section is calibrated to produce an identical output for a given input. The combination of these two processes achieved through CalFree™ allows an installer to compute the theoretical calibration of a given scale. This technique is slightly less accurate than using test weights, since it does not take into account the actual mechanical characteristics of the installed scale. System integrators and installation technicians who only need an approximation of calibration would find this process useful to confirm the operational integrity of the overall system.   Furthermore, factory calibrated analog sections also allow you to replace boards and be assured that the calibration of the replacement is identical to that of the board being replaced.

Cal Test and Calibration Maintenance

These two patent pending techniques help you assure the calibration of your scale is within tolerance over long periods of time. Cal Test is a sequence of up to 25 steps where an operator is directed to place test weights in specific locations. The weight produced at each step isautomaticallycompared against the test mass used and found to be within or outside of a given tolerance. Calibration Maintenance is used to initiate the Cal Test at specific intervals, either based on time or the number of weighings. Using these two processes can help you assure compliance with validation requirements dictated by your quality system.

Step Calibration and CalFree™ are two new innovative techniques that help you align the appropriate calibration technique with your real requirements, balancing accuracy with time, cost and practicality. Cal Test and Calibration Maintenance can perform a vital role in assuring your weighing accuracy is maintained and that compliance with your internal quality requirements is achieved.