hologram (Stranger)
03-27-04 14:21
No 497749
       What should be used to measure liquids accurately?     

I'm trying to figure out how pipettes and such work.  Can you get a pipette that has ml amounts on it so you can measure out your liquid?

  When one buys a pipette from somewhere like ebay do you have to also buy something to get them to pull up liquid?  The ones I see in the pictures look like long thin glass tubes and I don't see how you would pull liquid up with them. 		 
 
 
 
    Rhodium
(Chief Bee)
03-27-04 15:35
No 497760
       Pipettes     

Large pipettes (graduated in milliliters) and their associated pipet filler bulbs (http://www.cbu.edu/~mcondren/c214/pipet/3bulbpic.htm)




Pasteur pipettes (usually 2-3 mL) use small rubber bulbs to draw up liquids:



Now you can use the above keywords to conduct a fruitful google search for more information.
The Hive - Clandestine Chemists Without Borders 		 
 
 
 
    biotechdude
(Hive Bee)
03-27-04 16:42
No 497770
       pipette use     

Also remember to read the instruction on their proper use.  There are issues and techniques for correct selection, caliberating, fluid uptake, miniscus, fluid release, cleaning etc etc are built into the pipettes and fillers accuracy ratings. 

Or at least make sure u are consistently doing it the wrong way so the nett varience is negligable. 		 
 
 
 
    chilly_willy
(Hive Bee)
04-02-04 16:39
No 498764
       also..     

Also dont forget our friend the graduated cylinder.  Very cheap..and very accurate for more practical amounts of liquids 10-200+ml.  Their plastic counterparts are actually better than the glass ones as they dont tip over and break or form a meniscus which can throw off precision readings after you have smoked a little of the kind.  Polymethylpentene is the type to get as the plastic is crystal clear..and highly resistant to MOST any chemical you throw at it.
The shortest distance between two points is a straight line 		 
 
 
 
    methyl_ethyl
(Guardian)
04-02-04 20:29
No 498788
       higher accuracy     

And if you are looking for higher accuracy, there are always type A volumetric pipettes.  Rechargeable battery operated, adjustable, pipette aids are also very useful and are often more controllable than the bulbs.





     Unipolar Mania, It's good for life... laugh 		 
 
 
 
    Grouch
(Hive Bee)
04-17-04 17:19
No 501399
       Used for?     

What are you going to hypothetically use it for and how accurate do you need it?  Are you looking for something that measures only mL amounts or to the closest mL?

If you just need something that you can set and forget to dispense liquids with pretty good accuracy to the mL over and over again, I found bottle top dispensers very handy. 

http://www.eppendorf.com/en/?jump=http%3A//www.eppendorf.com/script/cat-nav.php%3Fc%3D1%26l%3D25&jumpmenu=8T

Look for the bottle top dispenser, Varispenser® plus/Varispenser for a picture of one. 		 
 
 
 
    pooky
(Hive Bee)
04-20-04 21:14
No 501963
       Weight     

If you have an accurate scale,that also works.1 ml H20 is 1 gram etc. 		 
 
 
 
    FlyBoy
(Hive Bee)
04-26-04 15:40
No 503204
       Good ol' days in Chem class     

I remember in chem class the pipettes that we used had a plastic fitting on the top with a wheel that you turn to draw up or push out liquid. If I had  pic it would greatly help out the both of us (*my explaination). Ah the good old days of titration.
Salt Bonds:  Cohesive? Adhesive? ??Chemical?? WTF? 		 
 
 
 
    methyl_ethyl
(Guardian)
05-01-04 19:11
No 504276
       Is this the contraption you are speaking of?     

Is this the contraption you are speaking of?  I have many in my lab, however I have never used them once.  crazy  How it would help you in titrative assay's I have no idea..... 


     Unipolar Mania, It's good for life... laugh 		 
 
 
 
    methyl_ethyl
(Guardian)
05-01-04 19:33
No 504279
       correct me if I am wrong     

You are saying that .1 mL  of water or 100ul of water is equal to 1 gram of water?  First of all that is a very risky statement.  1mL of H2O is supposedly equivalent to 1 gram of water at STP, AFAIK..  I have found that it depends on what you are weighing, that may have a significant effect on the materials weighed.. Whatever, it is all good....  I think that your initial "diagnosis" of the said situation is quite flawed.  No I am not the "typical" hive member.  I think you are wrong, and you should correct your statement.  i could be wrong, as always, and if you find that I am wrong, please back up your statements with pertinant information that will increase hive intellectual output.

love, as always,

m_e
     Unipolar Mania, It's good for life... laugh 		 
 
 
 
    Rhodium
(Chief Bee)
05-01-04 21:00
No 504289
       loss of space     

You are saying that .1 mL  of water or 100ul of water is equal to 1 gram of water?

No, he is saying that 1 mL = 1 g. He missed to press his spacebar - the period is part of the first sentence wink
The Hive - Clandestine Chemists Without Borders