Originally Posted by
topflightpro
How do I check the slope on my Quarq?
Originally Posted by
tetonrider
you need a calibrated weight. super important. there are a few ways to do it, but essentially you measure the zero offset with no weight then with the known weight.
you can do this with a simple spreadsheet or you can get the quarq app. with a quarq you need the wahoo ant+ dongle. with an SRM you don't need anything special.
here are some instrux quarq posted a while back:
Calibrate Slope Help
it's the type of thing that seems complex until you do it once. then it takes just a few minutes. hardest part is getting a weight that is both accurate and of appropriate mass.
>=10kg is ideal. get a certified weight if you can. others can tell you how accurate you want that weight to be. (solid engineering principles dictate that the accuracy should be a certain %age of the thing being measured, and in this case if the weight is off even by a small amount it can mess up the calculation--moreso with smaller weights than large ones.)
Just wanted to quickly mention that the App isnt necessary if you are just checking the slope. I know i can manually rnter the slope for my SRM using Edge 500, but i'm not as sure about Quarq
as for the spreadsheet, you basically check ZO offset with no hanging weight, record the offset number. Add one item of known masd, record the number; repeat as you see fit. Ideal set up would be two 10kg plates having known masses.
open any spreadsheet and type in the numbers, do a linear regression. Slope of the regression line is, well, the slope of your PM. It records the changes in the reading as the input torque is changed. Of course, you'll also need the right unit conversions.
As for calibrated weights, the scales at the Post Office is calibrated every month.