This may be the last version of our Newsletter in this format. This newsletter discusses our Portable Calibrator, LAC and has an article on measurement risk.
Features: New Calibration Certificates and QR Codes; Top 3 ASTM E74 Calibration Mistakes; Upcoming Events – Announcements and Dates
Features: Designing Force Adapters for Calibration; Quick Change Tension Adapters for Calibrating Machines; Upcoming Events – Announcements and Dates; Meet Our Staff - James Wagner, Chief Engineer
Features: 2-Bar Versus 3-Bar Universal Calibrating Machines; ASTM E74 Calibration – Simplified step-by-step instructions; Upcoming Events – Announcements and Dates
Features: Tips from the Cal Lab - SPC – Statistical Process Control in the lab; Good Measurement Practice – Keep your system in control with a 5 in 1 solution; Calibration Intervals – by Phil Smith; Upcoming Events – Announcements and Dates
Features: Load Cell Troubleshooting – Morehouse 7 Step Load Cell Troubleshooting Guide; Potential Measurement Error – Tension Links; Meet the Morehouse Staff – Barry Cook (Lab); Training Workshop – Announcements and Dates
Features: Lean Tips – Setup Reduction; Potential Measurement Error – Unbolting Load Cells May Not Product Repeatable Results; Meet the Morehouse Staff – William Lane (Design Engineer); “Specifying Accredited Services” – Column by Phil Smith
Features: Lean Tips - 5S or 6S; Potential Measurement Error - 4 wire versus 6 wire; Meet the Morehouse Staff - Brian Ruppert (Machine Shop Supervisor); "Single Measurement Bliss" - Column by Dilip Shah discussing the problems with a single measurement
Features: Tips from the calibration lab - Point of Use to Save Time; Potential Measurement Error - Loading Through Bottom Threads in Compression; History of Morehouse - A detailed history from the 1920's through 2015; Oops! I severed my Cable Again - An article about switching cables
Want to learn more about force measurement errors and the impact the wrong adapters can have? The wrong adapters can produce measurement errors up to 20 times that of when the instrument was calibrated. This technical paper provides greater detail on adapters for compression and tension calibration of load cells, mini load cells, washer load cells, s-beam, tension links, multi-axis, hand-held for gauges and other force measuring instrumentation. It goes into detail about to improve your force calibrations with the proper adapters.
Morehouse has been performing both ASTM E74 and ISO 376 calibrations for more than fifteen years. We have been calibrating in accordance with the ASTM E74 standard since its introduction in 1974, and performing ISO 376 calibrations since sometime in early 2000. Until recently, we assumed that the rest of the world and force community knew that the standards were completely different and that either standard could not be substituted for another. This paper explains those differences in more detail.
Measurement decision risk as probability that an incorrect decision will result from a measurement. Are you telling your customers instrument passes without considering measurement uncertainty? If taken to court, are your measurement defensible? This paper examines the proper way to make statements of compliance.
Having troubles understanding measurement uncertainty and how to put together a budget? This paper examines all of the components required to put together a full calibration and measurement capability (CMC) reviewed by Accreditation Bodies for your scope. This is a guide to calculating force measurement uncertainties and was published in Cal Lab magazine.
Article written by Henry Zumbrun for Cal lab Magazine.
What you need to know about dual range calibrations. Article from Test Magazine May 2016 issue.
Article in test magazine from Oct-Nov 2015 issue.
There is not a difference in repeatability and reproducibility between a 2 bar and a 3 bar Universal Calibrating Machine
Written and published in Cal Lab magazine April 2016
Article published in Quality Digest written by Henry Zumbrun (Morehouse Instrument Company).
Recommended steps for calibrating instruments in accordance with ASTM E74-13a. Published in Quality Digest Online in July 2016
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)
This blog describes the expected errors from using mass weights to calibrate force measuring instruments such as load cells, crane scales, dynamometers, hand-held force gauges, and tension links. We examine the error in using LBS instead of LBF and vice versa. Gravity is not constant over the surface of the earth. The most extreme difference is 0.53 % and using mass weights for calibration and then using the instrument somewhere else can result in significant measurement errors.
Without the Right Adapters a Force Calibration Technician is Nothing Short of Being Called a Miracle Worker
Think about that for a minute. Would you want a surgeon to operate on you with kitchen utensils such as a serrated knife? Then why do some people (management cough) expect or ask the force calibration technician to calibrate load cells, truck & aircraft scales, tension links, dynamometers, and other force measuring devices with whatever they have in their laboratory.
It’s been five years since ASTM E74 was last updated. The new standard ASTM E74-18 is released and this blog is going to detail some of the major changes between ASTM E74-13a and ASTM E74-18.
Guidance on Uncertainty Budgets for Force Measuring Devices Part 4. Calculating Uncertainty for Force Proving Instruments Calibrated to ISO 376
Morehouse CMC sheet will allow CMC calculation in accordance with ISO 376. The purpose of this blog is to provide guidance for determining the proper contributors of parameters for force measuring devices that should be taken into consideration when developing uncertainty calculations that support Calibration and Measurement Capability (CMC) uncertainty claim made on a scope of accreditation.
ISO 376:2011 Metallic materials — Calibration of force-proving instruments used for the verification of uniaxial testing machines standard explained. The ISO 376 standard is used worldwide, and it is a requirement for anyone calibrating in accordance with ISO 7500. If ISO 7500 is the requirement, then calibration needs to be performed in accordance with ISO 376 on the force-proving instruments used to certify the tensile machine. It is also the generally accepted force standard for most of the countries outside of North America for calibration of force-proving instruments such as load cells, proving rings, dynamometers, and other instruments used to calibrate similar types of instruments.
The article discusses the differences between ISO 376 and ASTM E74 in hopes to prevent intermixing of the standard as we had heard of companies using an ASTM E74 calibration to certify a tensile machine to ISO 7500.
Morehouse has been performing ISO 376 calibrations for over the last fifteen years. In this time frame, we have changed our ISO 376 certificate format three times. The latest change offers additional information such as calibration graph per run and is laid out in a way that is much more cohesive making it easier to read and understand