magenta coloured sponge in grey 226 cartridge, how queer!

[Tudor]

X-Acto knife

 

[PeterBJ]

Thank you very much Tudor, for the tip of using coins to verify the accuracy of a scale. Coins are made to tight tolerances, else they were useless in vending machines.

Loading coins onto my digital scale, I found that my 500g scale with a division of 0.1 g was mostly spot on, with an occasional deviation of +0.1g. This is typical behaviour of a digital measuring instrument, often accuracy is stated as +-x% of reading +-1 on last digit. It appears that x is small. I'm impressed by this cheap Chinese made scale. The reading is also independent on where the load is placed on the weighing plate.

So I'm confident these weights for the PGI-x20/CLI-x21 cartridges are accurate to within +-0.1g, and that the weights also apply to the PGI-x25/CLI-x26 cartridges, as the windowed and the opaque cartridges are very similar.

The weights are for new Canon OEM cartridges with the orange clip and the vent sealing tape removed:

PGI-520PGBK: 35.3g, CLI-521C: 20.3g, CLI-521M: 20.2g, CLI-521Y: 20.2g, CLI-521BK: 20.4g

So Ant, I recommend that you get one of these inexpensive digital scales. If you don't need to weigh objects weighing more than 100g, like some large HP cartridges, a scale with a load capacity of 100g and a division of 0.01g is even better.

 

[ThrillaMozilla]

Thank you very much Tudor, for the tip of using coins to verify the accuracy of a scale. Coins are made to tight tolerances,....

Coins wear and change weight. If you really want to calibrate a balance (it's called a balance, not a scale), for under $5 at Amazon.com you can buy a very good weight that is accurate to several decimal places. The main reason to check the balance is that weights depend on where you are on the earth. Even without calibration the balance you have may possibly be more accurate than any coin. But yes, coins are good enough to weigh ink in a cartridge.

 

[PeterBJ]

I thought that "balance" only applied to the old type of weighing equipment, with two trays, suspended from a beam?

 

[Tudor]

The weights are for new Canon OEM cartridges with the orange clip and the vent sealing tape removed:

PGI-520PGBK: 35.3g, CLI-521C: 20.3g, CLI-521M: 20.2g, CLI-521Y: 20.2g, CLI-521BK: 20.4g

Thank you for the measurements! The last time I had unopened OEM cartridges I didn't have a precise scale, so I used a kitchen scale and got 35 for the 525 and 21 for the 526. This is much better, will add them to the worksheet.

http://en.wikipedia.org/wiki/Weighing_scale

 

[PeterBJ]

Thanks for the Wikipedia link

I do know the difference between mass and weight, weight is mass multiplied by gravity acceleration or F=mg. G is not constant but is a function of lattitude. Maybe we should start using this formula when refilling? If we suppose the scale or balance was calibrated in Hong Kong, and you know your lattitude, a correction factor can be calculated.

The formula for g, as a function of lattitude: g = 9,80612 - 0,025865∙cos(2∙φ) + 0,000058∙cos^2(2∙φ), where φ er the lattitude and cos^2 means cos squared.

 

[Tudor]

Wait, doesn't everybody use this formula when refilling?

The link was for ThrillaMozilla.

 

[ThrillaMozilla]

I thought that "balance" only applied to the old type of weighing equipment, with two trays, suspended from a beam?

On second thought, I guess you're right, although the instrument does balance an electronic force against the gravitational weight of the object.

As long as people can buy those, er, scales, dirt cheap, I'd just like to encourage them to buy a calibration weight for just a little more.

 

[The Hat]

I thought that "balance" only applied to the old type of weighing equipment, with two trays, suspended from a beam?

On second thought, I guess you're right, although the instrument does balance an electronic force against the gravitational weight of the object.

As long as people can buy those, er, scales, dirt cheap, I'd just like to encourage them to buy a calibration weight for just a little more.

I wouldnt mess with PeterBJ, on a scale of .1 to 10 he is pretty well balanced..

 

[ThrillaMozilla]

Mettler balances
Sartorius balances
Mettler scales Oh, well, go figure.

But enough of this on this thread.