Custom High Temperature Load Cells for Downhole Applications Above 400 °F (204 °C) Donut-style (through-hole) load cells and compression fixtures on the bench at Morehouse. Put a cast-iron skillet with a plastic handle into a 450 °F (232 °C) oven. The pan will be fine. The handle will not. A strain gauge load cell fails […]
Force Calibration Safety: The Day Three Threads Let Go A technician set up a tension calibration in a 200 000 lbf (890 kN) machine, threaded the connection together, and started applying force. Only three complete threads were engaged. The internal threads stripped, the connection separated, and everything above the failure point released at once. Three […]
Two Degrees Off: What Mount Erebus Teaches Us About Measurement Bias I recently read 10x Is Easier Than 2x by Dan Sullivan and Dr. Benjamin Hardy, and one story in it made me think about calibration, specifically a paper I wrote three years ago on bias. Before we get to that, here’s more about what […]
Why Do Force Calibration Adapters Matter? The Measurable Cost of the Wrong Setup A load cell that reads to 0.005 % of full scale in the laboratory can degrade to 0.5 % of full scale, or worse, in the field, mounted with adapters that introduce bending, side loading, or torsion. Same cell. Same certificate on […]
How to Calibrate a Proving Ring: No Bridge to Hide Behind A digital proving ring: the displacement sensor replaces the micrometer and vibrating reed, and the indicator displays the deflection. A proving ring has no strain gauge bridge to do the thinking for you, even when a digital indicator does the reading. It is a […]
How to Calibrate a Cable Tensiometer: The Cable is Part of the Measurement A cable tensiometer never touches a load cell or a hook. It clamps onto a cable and reads the tension in it. That one difference makes it among the trickier instruments to calibrate honestly, because the cable itself becomes part of the […]
How to Calibrate a Hand Held Force Gauge: Mount it Square, Not by Hand A hand held force gauge is the most-used force instrument in most plants and the least likely to be held the way it should be. It gets pushed across a bench by hand, and the certificate inherits every wobble. Good hand […]
How to Calibrate a Crane Scale: Reproduce the Way it Hangs A crane scale spends its working life hanging from a hook with a load swinging underneath it. Calibrate it any other way and the certificate describes a scale that does not exist. That is the whole problem with crane scale calibration. The instrument is […]
How to Calibrate Aircraft and Truck Scales: The Tire is Part of the Measurement in Aircraft and Truck Scale Calibration Three different size adapters made by Morehouse on a 10 000 lbf PT300 scale. Will there be a difference in the measured values? We loaded the same truck scale to 20 000 lbf (89.0 kN) […]
