Author Topic: Analytical vs Digital  (Read 2977 times)

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tryin

  • Guest
Analytical vs Digital
« on: November 08, 2004, 10:43:00 AM »
What are the pros & cons of an Analytical scale/balance vs the pros & cons of a Digital scale/balance?

Below are my opinions:

Analytical

Pros:
Very accurate in the smallest of weight
Most have a windshield built in
Can be found relatively cheap

Cons:
Big bulky, not home lab friendly
Hard to calibrate

Digital

Pros:
Easy to calibrate (good ones have automatic calibration)
Small compact easy to store
Quick readings

Cons:
Not as accurate at smaller weight
Can be quite expensive

This is just what I thought up. If anyone can help out please reply. If any above are incorrect please let me know also.

maj

  • Guest
Depends on what you wanna weigh.
« Reply #1 on: November 08, 2004, 10:54:00 AM »
Depends on what you wanna weigh.  Being as though your already posting at the hive were going to assume some type of phenethylamines or tryptamines.  You can get digital lab scales that weigh hundreths .  I prefer Acculab myself.


indole_amine

  • Guest
exactly
« Reply #2 on: November 08, 2004, 09:16:00 PM »
Exactly, there are no advantages in mechanical scales these days - the digital ones are cheap and able of weighing in the miligram range (or at least 1/100th of a gram  ;) )...


indole_amine

Freemind148

  • Guest
I just bought a digital scale that can weight...
« Reply #3 on: November 09, 2004, 06:51:00 AM »
I just bought a digital scale that can weight upto 500g with accuracy of +/-0.02g and it cost me around US$100 (somewhat expensive, but every lab equipment is expensive in where I live as they are imported).  It comes with a standard 200g weight for calibration.  It took me a while before I decided buy this one.  But this is in the optimal range of what I intend to use.  I think it really depends on what you want to weight with it and the range and accuracy you require.

moo

  • Guest
Analytical vs Digital (whaat?)
« Reply #4 on: November 09, 2004, 07:55:00 AM »
But doesn't analytical only mean that the scale is very accurate (eg. 0.1 mg), and digital that it works based on digital electronics? To me all this sounds like comparing apples to oranges...  ::)

I've seen some digital analytical scales, the ones with which you could see how the weight of a paper that was handled earlier by bare hands decreased continuously as the moisture absorbed to the paper evaporated. I've also seen these three beam scales which are neither analytical nor digital.


maj

  • Guest
Absolutley Right
« Reply #5 on: November 09, 2004, 08:11:00 AM »
Analytical scales and digital scales...  Bascially the same damn thing if ya ask but the only differnece is with one you can measure to thousands(.001)and the other to ten thousands(.0001) if you please.  And your gonna spend a pretty penny on those .  Well for that fact any of them.  For fucksakes I highly doubt most people here are gonna need highly proficient analytical scales that weigh to that calibration.  So stick with the regular ole digitals and save your green.


Freemind148

  • Guest
This is what my understaning is on the ...
« Reply #6 on: November 09, 2004, 08:32:00 AM »
This is what my understaning is on the difference between "Analytical" and "Digital" scales.  Analytical scale is based on principal of beam-balance with a pivot and calibrated mass as comparator.  Manufacturers can add electornics to it to make its readout in digital format.  Usually it requires rather level top and closed case to minimize the effect of disturbances.

However, typical digital scale is based on"load cell' whose resistance changes with the mass sits on top of load cell and compresses it.  This usually have certain range that is 'linear' as most of the electronic device has certain range of 'linearity'. 

Of cource, I can be wrong and you might as well find out from the people who make the scale.

Chosing the right scale for you depends on your application amd how much you want to spend, I guess.

jboogie

  • Guest
i might bee wrong, but...
« Reply #7 on: November 09, 2004, 10:47:00 PM »

hest

  • Guest
*lol*
« Reply #8 on: November 09, 2004, 11:53:00 PM »

Jamiroquai

  • Guest
I prefer the twin-beams over the digi's
« Reply #9 on: November 10, 2004, 02:01:00 PM »
Digital scales are too easily ruined by carrying them around like a pack of cigs in the pocket as is easily to space-off and do. Whereas the twin-beams which do go to the 1/100th of a gram come with that nice hand dish and you can pre-set the desired weight and tend to the given weights & measures at hand.

I trust gravity a Hell of a lot more than storage in a pocketfull of shit(not that I even know this matters but something distorts the readings of a given mass)

To each his own, but twin-beams are value-priced and are meant to cusp the given substance itself who cares about tares and preprogramed bagweights?!

I'd take that dish and personally propose that it alone trumps them low batteries and blowing bags and unlevel flat surfaces and so on and so forth. Gravity is a constant. And yes I can't weigh with my stuff already in the bag but who cares if you ask me.

ChemoSabe

  • Guest
Digital vs ...
« Reply #10 on: November 10, 2004, 11:38:00 PM »
jamiroquai wrote...

Digital scales are too easily ruined by carrying them around like a pack of cigs in the pocket as is easily to space-off and do. Whereas the twin-beams which do go to the 1/100th of a gram come with that nice hand dish and you can
  pre-set the desired weight and tend to the given weights & measures at hand.


In my own eperience this statement is 100% true. Started out with a triple beam. Johnny law stole it. Got a small digital, it worked for about 3 months and then it got weird on me (inaccurate) Then happily procured the same model of triple beam that I started with and have stuck with it ever since.


biotechdude

  • Guest
comments
« Reply #11 on: November 11, 2004, 12:04:00 AM »
As an undergrad, my chem professor told me that as a rule of thumb, drop the last decimal point from digital scales (as its worthless)

Meaning, if your scales are 100g +/- 0.1g then it should only be used for measuring whole grams.  Further, if measuring points; get a digi that goes to .01 or .001.  Even then, the build quality will determine how quickly it looses accuracy.  Moreso, carrying it round in a pocket will quickly fuck it up - they are precision instruments after all.

The beams are great for accuratly pre-weighing retail bags etc.  But a bit impractical whilst wheeling and dealing (jewellery of course..).  It is important to have a set procedure for weighing and minimise external factors such as wind and ensure the surface on which you weigh is hard and flat.  You can end up unknowingly ripping off the buyer or yourself.  Also, it is wise to carry caliberation weights to handle any disputes if they arise.

Freemind148

  • Guest
Digital scales rely on accuracy of electronic...
« Reply #12 on: November 11, 2004, 08:12:00 AM »
Digital scales rely on accuracy of electronic components.  the load-cell itself is rather stable and reliable.  However, the electronic circuits that process the load-cell's output may or may not be.  electronic components such as resistors, capacitors and oscillators may change value, leak and drift over time (aging) and are affected by temperature.  If the manufacturers use cheap components and have design that does not have any temperature compensation, there scales won't be all that robust nor reliable.

Most of the digital scales would reuire warm up time (15 minutes) to allow all the components to reach operating temperature etc.  It is then best to do calibration with standard weight.  It would be preferable to have two standard weight near the upper end and another one near the low end since this allow you to check it's linearity.  Unfortuntely digital scale typically comes with one standard weight in the middle of its range; therefore, you may have to buy one or two more if you are serious and critical about the accuracy of the entire range.  If the results show see-saw behavior i.e good at one end of the range but not the other, then the balance is no longer good.

I agree that if you are really picky about the accuracy, nothing beat mecahical scale that is based on beam-balance.

Tdurden969

  • Guest
Swim loves his Sartorius lp2200s digital ...
« Reply #13 on: November 11, 2004, 02:45:00 PM »
Swim loves his Sartorius lp2200s digital analytical balance.

2.2kg max with .01g readabillity

Course you can't carry it in your pocket.