Several organizations and publications reference or insist on maintaining a 4:1 Test Uncertainty Ratio (T.U.R.) without understanding the level of risk that they may be subjecting themselves to. This blog examines the probability of false accept and why the location of the measurement may be more important than T.U.R.
This blog is going to discuss the Morehouse Concrete Compression Machine Calibration kit and the potential error sources associated with using material with a different hardness than what the system was calibrated with. Morehouse has created a kit to minimize the common compression error sources while providing a lightweight portable solution with an ASTM verified range of forces of better than 400 lbf through 600,000 lbf (660,000 lbf is possible) for calibration of concrete machines to ASTM E4.
Has anyone ever wondered if there is a difference in calibration results if the time interval between successive loadings is changed? Is faster better and does it matter if the calibration takes 10 minutes on an automated machine pictured in figure 2 below, or two to three hours at NIST or a comparable lab with deadweight calibration systems?
This blog discusses the most important attributes of great force calibration machines such as being plumb, level, rigid, and square and error sources associated with not having a machine that has these attributes.
Morehouse 2,000 lbf Tensiomenter calibrator to calibrate Cable Tensiometers Safely, Load Cells, Crane Scales, Hand-Held Force Gauges, Dynamometers, and More.
Any organization that is accredited must account for the uncertainty of their standards. The following are guidelines to assist in calculating the measurement uncertainty for dead weight primary standards.
This post describes various force standards that are often used to calibrate force sensors and other devices. It discussed in detail the advantages of deadweight machines for the best calibration results. It then goes into detail about what it takes to calibrate a load cell properly.
Morehouse Training at NCSLI 2018 in Portland. We will be teaching two tutorials, one on force and one on torque as well as presenting at Session 5A and the Airline Committee meeting.
Load cell stability can potentially consume your uncertainty budget, cause the force measuring device to be out of tolerance, cause all measurements between the last calibration and the current calibration to be recalled, raise the accuracy specification of the system. This post covers what instability is and ways to potentially reduce instability.
Some ISO 17025 accredited labs performing torque calibrations may not entirely be considering the effect on the uncertainty from Torque Measurement Error from Applied Force Direction (cosine error)