Why read this article? If you use load cells, the chances are that someone is setting them up using a 2 point or 5 point span calibrations. This type of setup often has high errors. This article discusses a more accurate way to eliminate the majority of these errors. Morehouse goes on to explain what mV/V is and why using a calibration curve may be the most accurate method for displaying the results in engineering units such as lbf, kgf, N.
Curious as to how to calculate the resolution of the force-measuring device submitted for calibration, or how the laboratory calibrating your device is calculating a value for resolution. Are they calculating it correctly? This post describes the importance of resolution and how to calculate it.
Reproducibility is often confusing, and many find the topic difficult. However, capturing values for repeatability and reproducibility of a measurement process for determining a lab's calibration and measurement capability does not have to be hard. This post offers simplified solutions as well as several references as to what reproducibility is.
A body of known mass can have different weights (force applied by gravity) based on its location on earth. This simple concept has been a significant source of error in mass measurement, particularly when the measurement device is calibrated to force at a different location. The good news is that with the right information, this error can be corrected mathematically. Morehouse’s Local Gravity App helps you do this correction based on the GPS data from your cell phone. AVAILABLE ON GOOGLE PLAY FOR ANDROID DEVICES
S-beam or S-Type load cells were designed for several weighing applications and may not be suitable for several force applications. Any misalignment in the load path will produce significant measurement errors. This blog discusses the error sources and how one can try and correct them.
This blog details three things needed to properly calibrate aircraft scales. The 3 things are as follows: the right equipment, the right adapters, and the right process. Using a machine that has bending or is not level will produce large errors, not simulating the tire of the airplane or truck can produce large errors, and not properly converting force to mass or mass to force can all lead to incorrect results and errors of well over 2 % on a scale with a tolerance of 0.1 %.
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?