u/13abysauce

1st time getting it the value was enormous with two big styrofoam boxes with meatballs fish, sauce, mash potatoes, and a piece of cake and was given by the kitchen worker and it still tasted pretty good.

now the last two times has been abysmal and was given to me by the cashier after having to wait 10-15 minutes each time. now we just got two small boxes with two “plates“ always just fries and dry chicken tenders and then fish with bland peas and mash potatoes that honestly doesn’t look like an actual plate size.

trying to figure out what happened because they still are highly rated and I’m wondering if it’s just a chance thing or if they have changed something internally. cause now it’s the cashier handling the transaction and they always give a standard two plates and for some reason it’s always damn chicken tenders with a small handful of fries. definitely not worth the travel, wait time, and then having to transverse the entire damn store to get the small boxes that I’m seeing others post.

Hey all,

I'm calibrating an instrument to deliver solvents which means I have to calibrate the delivery using the solvents that will be used. I have calibrated all of the solvents except for the last one which is DCM but I've been told that its easier to do with methanol since they both have the issue of vapor pressure skewing the pipetting accuracies but methanol maybe less so.

So far I have calibrated the system with DMF using 2 mL and weighing it on a scale by drawing out 1 ml *2 using a 1 mL pipette. This pipette would consistently give me a 954.0 - 958.0 mg weights for 1 mL which matches with the density of DMF which says its between 0.95 -0.96 depending on temperature. Using this I figured that my pipette is calibrated and fairly accurate.

Now the problem is that I'm doing the same with the methanol but for 1 ml of methanol it gives me an amount thats noticibly off. 1 mL should be 791 mg but I'm getting 833 consistently. I conditioned the pipette tip so that it wouldn't drip but I also know that for a solvent like DCM when the tip is conditioned the pipette also has a habit of drawing way more than 1 mL. I figured that this is happening with the methanol as well and thought that 42 mg which is around 32 microliters discrepancy is not unreasonable; however, I also thought that the methanol which is definitely not dry would have a higher density since it has absorbed some water from the air.

I just wanted to hear how some of you might handle this because I want the system to at least deliver 2 mL, that being over 2 mL is okay but definitely not under. I was thinking I'd just ignore the effect of methanol/water mix on the density, but I wasn't exactly to what degree the density of methanol will change as it draws more water from the air.