AnD FX-120i Calibration Question

[tthomp302]

I have an FX-120i with an autotrickler V4 attached. I calibrated it with the 100 gram weight just as the instructions state. My glass cup before calibration weighed 776.5 grains. After calibration it weighs 777 grains flat. Before I calibrated it, I took my normal load and threw it and put it to the side so I could compare what it would be after calibration. I was expecting a change in the charge weight since there was a change in the cup weight, but both before and after weighed out to a perfect 49.2. Is this common?

 

[powderbrake]

Until you calibrate, you have no idea what the scale will display.
Assuming you calibrated correctly, accept what it says and move on.

 

[Evan]

You should consider investing in some check weights. I have a 10gn and two 20gn references that I use to check any scale I use. I increment 20, 40, 50, 30, 10 by adding and removing the weights. If it hits each weight correctly then I know the scale is good to go and doesn't need to be calibrated.

 

[Stumpy1]

What Evan said above is good advice. That should give you some confidence in your system.

I calibrate before every use -only takes a minute and yields confidence.

Also of note, the temperature of the room (and therefore scale) WILL affect the numbers you see as a tare weight on your glass cup. Don't sweat these normal variations.

It is important to note that these are sub $1000 balances and should be viewed as such.

As a side note, the last analytical balance I bought before I retired from the Pharma industry was over 10K, lived on a 400 pound chunk of granite, and had a built in ionizer.

Frank

 

[R.Morehouse]

Electronic scales that are not running off a battery should be run through a line conditioner.

Regards
Rick

 

[whatsupdoc]

Make sure the scale is perfectly level and warmed up.

I use a 50 gram calibration weight on my FX300 (same as FX120 larger capacity).
Once the scale is calibrated I switch the scale to grains and record the calibration weight. Every time I power up the scale I check the scale display value against the previously recorded calibration weight.

If it matches I know I am good to go.

 

[David101]

The difference in the scale weight for your glass and the load are a bit like MOA the change in the load weight was so small that it was below the sensitivity threshold of the scale. However the Glass which is closer to the full scale weight has changed a larger amount probably of the same % load but as it is further away it is a larger overall change. The scale is calibrated at a point which the manufactures belive will give the best overall result for the scale of the unit. If you read the specs of many instruments they have a minimum point on the scale that is the limit of the specifications or the specs change for readings less than 30% of full scale. Just an example not particularly for these scales.

 

[JMayo]

The cup will pick up a small amount of weight from residue and oil from your hand... You'll learn your system as you use it more.

 

[divingin]

Your empty cup changed by a half a grain (a 6/10000 shift, if my math is right.)
Change in the measured charge should be about the same as the cup, which I make to be .03 grains, or about the weight of a kernel of powder.

All that assumes that I'm not off by orders of magnitude. I offer no guarantees. But yeah, I can see where you don't get a change.

 

[Martin52]

If changing over scales - the FZ (as opposed to the FX) has internal calibration.

 

[cheek9075]

Your empty cup changed by a half a grain (a 6/10000 shift, if my math is right.)
Change in the measured charge should be about the same as the cup, which I make to be .03 grains, or about the weight of a kernel of powder.

All that assumes that I'm not off by orders of magnitude. I offer no guarantees. But yeah, I can see where you don't get a change.

Agree! Not that much change in weight ar over 750gn, you probably will not see any change in weight at less that 50gn.

 

[Sandstorm]

I dont give my A&D a second thought, Its always been good to go.

 

[Dave M.]

Electronic scales that are not running off a battery should be run through a line conditioner.

Regards
Rick

What line conditioner do you suggest for the Fx120i?

 

[Sandstorm]

I use a Trip lite.

 

[R.Morehouse]

What line conditioner do you suggest for the Fx120i?

Tripp Lite. I don't have the model number, I sold it with the FX when I chose to go back to my old method of aiming a small webcam at a Parker tuned beam scale and looking at it on a laptop.

Regards
Rick