Anything wrong with this analytical balance?

hidden cost

have you budgeted for a suitable callibration weight ?

OIML R 111-1: 2004 ........ class E1 (or E2 or ASTM E 617-97 (2008) .... class 0)


P.S. 0.1 mg in 100 g is 1 ppm ... bouyancy due to air density (1.225 mg/cc) comes into play.

Chinese eBay M2 weights in chrome finish are of variable plating quality, one of four 100g weights that I have is corroding

[Edited on 24-10-2016 by Sulaiman]

I haven't had good luck with Chinese equipment in the past. My recommendation, and what I did, is to look for a used analytical balance from a reputable company such as Mettler or Ohaus.

I managed to snag a Mettler AE160 for $200, and they pop up for around that amount from time to time. It has a built in 100g calibration weight, 0-160g range, and 0.0001g precision.

Sure, it's a bit older, but it was a huge step from the $20 Chinese scale I was using before, and I've never had any reason to doubt the accuracy.

Never buy the "no further testing" balances though, or balances which don't have pictures of both a correct zero weight and accurate measurement of a calibration weight, as they almost certainly are nonfunctional, or have missing load arms (talking from experience here.)

[Edited on 10-24-2016 by gdflp]

Although digital scales such as the ones you are looking at are good, are they necessary ?
For chemistry, where the next most accurate measuring devices are class A volumetric glassware, with 0.1 % accuracy, why would you want greater accuracy ?

Might it be better to have say three separate scales ?
e.g. 30g x 1mg and 300g x 10mg and 3kg x 100mg
probably with callibration weights <$100.

Three scales for 1/4 to 1/10 the cost, no fear of damaging expensive equipment, sufficient accuracy, and adequate range of weighing to cover most experiments.


P.S. a 250 ml beaker of water at 25 C in ambient temperature of 25 C loses c1 mg/sec by evaporation.
(dry air at 0.5 m/s, if my calculations are correct
So even if cooler and slightly humid air, you guys with 0.1 mg resolution scales should be able to watch/measure the weight decrease in real time.

O.K. ... now I want a precision balance

[Edited on 25-10-2016 by Sulaiman]

Quote: Originally posted by Sniffity

I'm between this two models: 1.- http://www.ebay.com/itm/LED-Lab-Analytical-Balance-Digital-

Quote: Originally posted by Sulaiman

have you budgeted for a suitable callibration weight ? OIML R 111-1: 2004 ........ class E1 (or E2 or ASTM E 617-97 (2008) .... class 0) P.S. 0.1 mg in 100 g is 1 ppm ... bouyancy due to air density (1.225 mg/cc) comes into play. Chinese eBay M2 weights in chrome finish are of variable plating quality, one of four 100g weights that I have is corroding [Edited on 24-10-2016 by Sulaiman]

"So, the next question is:
How many people reading this habitually weigh things to 4 figures (or more), but don't do the buoyancy correction?"

me

Quote: Originally posted by Sulaiman

"So, the next question is: How many people reading this habitually weigh things to 4 figures (or more), but don't do the buoyancy correction?" me