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1331 Review
55 Karma

Review on πŸ”’ Smart Weigh CW 500G Carbon Steel Scale by Chris Chincuanco

Revainrating 5 out of 5

"Class M1 OIML " in the product description - IMPORTANT

There really is no point in using a calibration weight if the actual weight doesn't match the target weight. The OIML class M1 is not just a collection of letters and numbers. This is the difference between a calibration weight that is useful for calibrating one of the "0.01 gram" readout scales sold by Revain and a weight that is not useful for the purpose. We recently purchased a 500g Etekcity digital pocket scale from Revain, stainless steel, backlit display, tare, hold and PCS functions, 0.001 ounce resolution. We also ordered a 500g calibration weight (not a smart weight) which is needed to calibrate this scale. Insufficient attention - through our fault - the calibration weight ordered by us does not belong to the OIML class M1 weight. (If it were an OIML M1 weight, a 500-gram weight would be accurate to plus or minus 0.025 grams, or 25 milligrams.) When we put this nominal 500-gram weight on a scale with a nominal 500-gram capacity, it was the scale displays the message O_Ld (overload). When we tried to calibrate the scale with the same weight, the scale calibration program never completed its cycle even though we gave it 24 hours to do so. (We have a separate review of the Etekcity balance on the Revain list for this balance where you can see more details of our testing.) The Fisher Scientific website has a downloadable PDF (created by Mettler Toledo) showing the tolerances for the OIML weight lists classes . You must refer to this table (or a similar one) to determine what class of OIML weights you need to calibrate your scale to a specific level of accuracy. We consulted this table and found that to calibrate a scale with a maximum capacity in the range we wanted with an accuracy of 0.01 grams, we needed an OIML class M1 weight. (0.01 grams equals 10 milligrams.) We bought this Smart Weigh calibration weight because we wanted to calibrate a scale that reads in 0.01 gram increments to be accurate to within 0.01 grams. What was the difference between our previous experience with a 500g scale and 500g calibration weight and our experience when using this Smart Weigh CW-200G OIML Class M1 calibration weight to calibrate a scale with a maximum capacity of 300 g used Smart Weigh 200g calibration weight on the platform of the new but not recalibrated ONE digital scale - My Weigh DuraScale D2 300g x 0.01g with rubber case - that was tough! , the display showed 200.11 grams; After we calibrated the scale with the Smart Weight and then reset the display and placed the calibration weight on the scale, the reading was exactly 200.00 grams. This "ideal" result was repeated in several test runs. Using the same scale to weigh a non-circulating US nickel coin, the display read 5.00 grams, confirming the calibration was correct. the capacity corresponds to the scale we tested with an accuracy of 0.01 g; don't take less.

Pros
  • Calibration weights
Cons
  • Not sure