Strange PGI9 behavior

[rodbam]

I have my mat black (MBK) cartridge filled with IS gloss optimiser to reduce the gloss differential in my prints but what is strange is the ink monitoring system is saying it's low on ink when it's still 3/4 full. This morning I reset the 3/4 full cart & carried on putting GO on my prints & now I'm getting the Low ink warning & still about 1/2 full. It looks like I'm getting the warning when only about 1/4 of the GO has been used.
Does the Pro9500 have some optical sensor that is looking through the clear GO thinking it's mat black & therefore must be near empty? I thought it was just the chip that controlled the ink count. Now I just take the cart out & weigh it, reset it & put it back in the printer, there's no point in refilling for just a 1/4 use a.

 

[jtoolman]

That might indeed be the case! I never thought of the Prism being fooled by the clear fluid since is id expecting some sort of density. I don't it is color specific but even yellow ink is dark enough. To the prism, GLOP may simply looks the same full or empty.

 

[mikling]

There is no optical sensor on the PGI-9. It is purely estimated by the chip with no optical backup.

http://www.precisioncolors.com/PGI-9_Internals.html

Either the discharge volume when using gloss optimizer is lower than when ink is used or the chip is running down too fast.

Wait for Hat to comment about what he has found in the past.

 

[The Hat]

Mike is right there are no optical sensors on or in the PGI-9 cartridges; its probably an optical illusion on rodbam part.

Seriously I use the Glop in my PGI-9/PGI-7 cartridge set and have faced the same similar problem
with my ink monitoring, but not as bad as rodbam.

My monitoring is running about 25% ahead of usage but no more, when my carts show low they are in fact only at about half way,
I think is just down to the viscosity of the Glop been slightly slower.

Its actually a good thing to have it that way because it certainly stops you running out of the stuff
and later cursing your own stupidity for letting it happen in the first place.

The OEM PGI-9C Glop is far thicker than I.S. Glop and as I know only too well it should never be used in any PGI-9 cartridges,
when it boils it turns into a solid gel like substance (Like a jelly fish).

 

[websnail]

Wondering out loud if the issue is that the cartridge is not feeding GLOP to the printhead properly, in which case there's a concern that the printhead nozzles aren't getting sufficient coolant and maybe suffering damage.

Is there any way you could swap in one of the original PGI-9MBK cartridges with the appropriate ink to test if the system is still working as it should?

Just a thought but given the 100 price tag on the heads I'd hate to see you blow it..

 

[The Hat]

When you print GO onto your photo you can clearly see the solid coverage when it still wet
so if its not printing correctly then the print head will be fried most definitely.

I use my previously damaged print head when I overprint with the GO on my iX7000 and then change it and the GO filled cartridges out
and refit my other print head with ink filled cartridges so if there is any damaged to the heads then I have not noticed it.

When I used my Pro 9500 to print the GO just the same as rodbam is doing with his now,
I never had a problem when changing it back to print in matte black I always got a perfect nozzle check afterwards,
so maybe the juries out till rodbam does a nozzle check with his matte black again..

 

[mikling]

It's likely that the boiling point of the GLOP or specific heat capacity is different from the normal base of the pigment ink. If this is the case, then there is more heating time involved. This means it will actually boil less and have less vaporization time and as a consequence less discharge volume for the same print instruction. Thus less volume is used for the same cycle compared to Matte Black ink. The fact that HAT also noticed a similar smaller discharge volume is likely indicative of this aspect.

 

[rodbam]

I'm due to put the real mat black in soon & will check it out but I don't think there's any problems because every time I take the GO cart out & exchange it for the real mat black it seems to print perfectly. I'm doing a lot of B&W prints on Canon Fine Art matte Natural paper which is 100% cotton so the printer is using the mat black cart plus some colour carts & it prints beautifully so I very much doubt there;s any problems from using the GO...............yet
I think it must be like you have said & the GO just squirts differently fooling the chip count, Mind you everytime I change from GO to Mat Black I have to run off 2 or 3 A4 pages of plain paper to get a nice solid black from the MBK & that would show up any problems a.
Thanks all

 

[websnail]

It's likely that the boiling point of the GLOP or specific heat capacity is different from the normal base of the pigment ink. If this is the case, then there is more heating time involved. This means it will actually boil less and have less vaporization time and as a consequence less discharge volume for the same print instruction. Thus less volume is used for the same cycle compared to Matte Black ink. The fact that HAT also noticed a similar smaller discharge volume is likely indicative of this aspect.

If that's the case then it would seem my concern regarding the cooling element would be non-existant as, if anything, the nozzles would be getting more cooling than the other ink nozzles.

Sounds like a win, even if it is messing with your head Rod

 

[rodbam]

One day Martin I'm going to be as brainy as the Hat