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
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
This paper will describe our calibration process, including the calculations of our Calibration and Measurement Capability(CMC), as it appears on our scope of accreditation.
This paper describes NPL’s 2 kN·m torque machine — Now at Morehouse Instrument Company — a lever deadweight machine with a vertical torque axis and an uncertainty of ±0.002 %. Despite the greater difficulty in applying torques to a vertically mounted transducer, this design was selected as it enables a symmetric “pure” torque to be applied. In addition, this design provides adaptability, enabling comparisons with the application of asymmetric torque and “on-thefly” torque calibrations to be studied.
If you get everything else correct and choose the wrong indicator, the overall system performance can suffer. This blog is going to better detail three specific indicator types. These are: 1- An A/D indicator that requires a computer to read the display 2- A battery powered portable indicator with minimal span points 3- A versatile indicator that can be used with several span points or accurately display mV/V through calibration.
Guidance on Uncertainty Budgets for Force Measuring Devices Part 3a. Calculating Uncertainty for Force Measuring Devices for Measurement or Verification of Force Using Non-Linearity
What is acceptable for a force calibration uncertainty budget when the device is not calibrated to a known standard and just to a couple manufacturer's specifications. This document aims at helping laboratories calculate force measurement uncertainties for Force Measuring Devices for Measurement or Verification of Force.
Guidance on Uncertainty Budgets for Force Measuring Devices Part 2. Calculating Uncertainty in Accordance with the ASTM E74 Standard
The ASTM E74 uncertainty appendix does not align with ILAC Policy for Uncertainty in Calibration ILAC P-14 which can be a problem for any accredited calibration laboratory. The purpose of this post is to combine the ASTM E74 calibration method, ILAC P-14, and JCGM 100:2008 together to help labs calculate measurement uncertainty per point throughout the loading range with the appropriate coverage factor k to meet their accreditation requirements.
Guidance on Uncertainty Budgets for Force Measuring Devices Part 1. Why Do We Need a Guidance Document?
This is part 1 of 4 total blog posts. This post deals with why Force Calibration needs a guidance document. The hope is to expand each of these posts and let them stand on there own to a specific force application.
A torque wrench is one of the most indispensable tools to have in your toolbox. Before choosing the one perfect for your requirement, you need to be aware of the various types of torque wrenches available, their calibration and factors affecting the calibration. All of these points are essential. Let’s take a look at them
This blog analyzes the effects of overshooting a test point and the error of doing so. Various calibration laboratories are using hydraulic, screw, and other force calibration machines where it is difficult not to overshoot a test point. By talking about overshooting a test point we are referring to loading past the desired point and then letting the creep in the hydraulic system naturally decrease the force point. Overshooting the force point to 2543 lbf, when the test point is 2500 lbf and waiting several seconds until the reference standard reads 2500 lbf.
Not choosing a calibration provider who follows published standards, calculates risk properly, and has open communication with customers about the importance of calibrating the instrument, in the same manner, it is used is critical to lessening measurement risk and ensuring the repeatable results. If these steps are not followed OOT (Out Of tolerance) situations are very probably and these are never cheap. Thus we wrote the top 5 costly calibration mistakes for force measurements.
This blog details some of what one would go through to present a tutorial at MSC, or NCSL International. This particular blog is on a Torque Tutorial Morehouse Presented at NCSLI. This is the one course we have been doing off site. Most other training is done at our facility with our equipment.
Tips from the calibration laboratory: How to calibrate button type load cells. Button load cells cause problems during calibration from misalignment to thermal issues. Using the proper adapters can improve the performance of this kind of load cell. This blog demonstrates how to achieve good results while calibrating a button load cell