I'm going to feel like I'm spamming the forum a little here of late, but I figure they are all valid questions. 

I'm experiencing some.. interesting HP and torque figures (my 150hp estimated car made 11500hp earlier today 🙂 ) 

I realised then that I had failed to calibrate the load cell. 

I have a 500kg load cell, supplied with my hardware blue box. 

I've zero calibrated it in its installed position (I originally took it out and desk calibrated like in the video from Jostein- before realising that was incorrect) 

I have a few issues- 

1) my load cell reading is "jumpy" 

Calibrated for zero, it then moves to -2 then +4 and jumps in between. 

I've ruled out interference from other cables and have isolated it as much as possible as suggested in other threads (unplugging laptop,moving away from everything etc) but no change. I'm not sure if such a minor "jitter" will impact on things? 

2) where do I place a known weight to calibrate and how heavy do I need? 

I've read 20% of Max load. 

So I need to stack 100kg of weights. 

But do I place them directly above the cell, at the end of the load arm? Or do I sit them further in board on top of the edge of the brake itself 

I'm assuming out on the load arm, above the cell is the best?