Weighing BP and Calibration Saga

[Rocketclar]

Today I decided to prepare some deployment charges for an upcoming launch. While the actual powder load density of BP is about 1gm/cc, I prefer to weigh my deployment charges using a jeweler’s scale vs using volumetric loading. So, today I turned on my scale and tared it. I always run a quick check using some standard weights. Normally, the scale agrees well with the 1 to 3 gram standard weights (most of my charges are in that range). However, today, they were off by a little more than 10%. Hadn’t seen this before but I suspected low batteries even though there was no low battery icon. Yep, had to replace the batteries. Rechecked, and still off. Fortunately, the scale has a calibration mode so I ran that using the standard weights required. All good. 10% error might not have caused a problem especially since I run redundant with the backup charge slightly larger, but why take the chance? Probably just stating the obvious, but checks and recalibrations are important.

 

[John Kemker]

Always a good thing with any scale.

 

[Sooner Boomer]

Calibration tip; a nickle weighs 5 grams.