EC997 Dyno Load Cell Calibration Procedures
There is no simpler dyno calibration.
Turn on Power on:
Black Box (green light will be on on current DAQ production units)
Go to the TEST Screen. (pre version 6.04 software may have this on the GRAPH Screen)
Go to upper, main menu, LH click on Setup. Do 1 LH click on Calibrate Load Cell.
The Calibrate Load Cell box appear.
Look at upper green text box - Verify that the numeric value showing is the same number that is stamped on your heavy, black calibration weight .
Remove EDDY current brake cover on the dyne chassis. The standard covers are steel and the custom covers are custom cut diamond plate aluminum or stainless steel.
With the drive roller stationary (as it would probably be if you didn't have an "in gear", running vehicle on it) , click on ZERO. (of course it wasn't moving - why would you take off the brake cover if the dyno was rolling????)
After you click ZERO, red box on the bottom right should be flickering a few .001's of a pound in the .000 area. If it's not flickering, then you don't have communication from the black Box to the computer. Check Black Box power and cabling. OK?
What we've just done is to tell the EC997 Software that the amount of voltage that is being produced by the load cell, right now, is the amount of voltage that passes through that S shaped load cell when there is absolutely no load on it.
Now.......
Place Black Calibration Weight on the forked torque arm, fully pushed towards the brake coils.
DO NOT, NOT, NOT DROP the weight onto the arm.
You WILL damage the load cell!! Most load cells / Strain gauges are not meant to have sharp loads applied. In operation, the dyno load is actually very "softly" applied.
Note: Just to make sure, the calibration weight should be dead centered over the load cell mounting bolt in the torque arm when installed to it's stops. Eyeball it. If it's not right, it's pretty obvious.
After Black Calibration Weight is on the arm, Click on SPAN.
Check that the bottom right red box reads within .010 pounds or so of the calibration weight's value. It should be flickering a few .001's of a pound.
What we are doing here is telling the software that "when this XX.xx pound weight is dead centered over the load cell, that IS XX.xx amount of weight and this IS the amount of voltage you will be seeing from the load cell.
Remove calibration weight.
So -now we've told the software that "X" load cell voltage is ZERO load and "Y" load cell voltage is XX.xx pounds of load (aha! "brake torque"!!). And magically! 1/2 of that voltage is 1/2 of your calibration weight's load (torque, again) and 2x the voltage is 2x the torque! Woohoo! The magic of electronics!
So - just to make sure - look again - weight off, should be ~.000 and weight on, should be XX.xx (whatever is stamped on your cal weight and in the green box)
Congratulations: you've now calibrated the software and load cell to within a few thousandths of a pound of torque.
If the final zero and weighed checks out to your satisfaction, LH click on "Save and return to Test".
Replace Eddy Current Brake cover.
You have now calibrated your EC997 load cell
5 minutes of checking for 100% TRUE HP accuracy and repeatability with other EC997 dynos!
I would do this monthly:
Load Cell Calibration
Grease bearings (Mobilith AW2 grease avail. direct from Factory)
For reference - if the dyno was "off" at zero, by .3 lbs, the actual readings of the engine torque reading would be only off by .1 pounds due to the aprox. 3:1 tach ratio on a sportbike or even less on an offroad bike or quad.
That's perhaps less than .05% error - or a an error of .05 to .1 hp (that's one tenth of a horsepower) on a gsxr750's peak readings - and that is FAR below the ability to absolutely and consistently control the temperature of the engine's case temp, intake port temp and dynamic air inlet temperature -