Weighing by Transposition

1 Page 1 SOP No. 6 Recommended Standard Operations Procedure for Weighing by Transposition 1. Introduction 1.1. Purpose This method eliminates possible. error in comparison of weights when using an equal-arm balance, due to a sma... Open at page → 2 Page 2 third weighing is made to determine the sensitivity of the balance under the load conditions. 2.3. Apparatus/Equipment 2.3.1. Equal arm balance of capacity and sensitivity sufficient for the weights tested. The index sca... Open at page → 3 Page 3 2.5.Procedure 2.5.1.Thefollowing weighing sequences may beused: Option A Measurement No. Left Arm R.ight Arm Observation 1 X +txl S + ts 01 1 2 S+ts X + ~ 02 2 3 S+ts+ sw X + tx2 03 2 Option B Measurement No. Left Arm Ri... Open at page → 4 Page 4 scale. Read and record all data and the sum of the turning points, 02. 2.5.3.3. Observation 3. Without disturbing weights already in place from Observation 2, add a small calibrated sensitivity weight (sw) to the left ar... Open at page → 5 Page 5 KS(l !I - 3.2.2.1. Optional Sequence A _ PA~ 01 - PSl 2 KSW(l - PA ) Kt + Kt 02 Psw sl s2 (. + 1 03 - 02 2 2(1 - ;~) Kt +Mt xl x2 _ PA )_ Pts PA 1 - Px 3.2.2.2. Optional Sequence B Ksw 11 - P A ) Kt + Kt _ PA\l 02 - 01.... Open at page → 6 Page 6 4. Assignent of Uncertainty The limits of uncertainty, U, include estimates of the uncertainty of the mass standards, Us' plus the uncertainty of measurement, Um, at the 99.73% level of confidence. The latter is estimate... Open at page → 7 Page 7 Appendix Transposition Data Sheet for Equal-Arm Balance (Option A) Test No.: Sheet No.: Date: Item Identification: Balance: Standard Identification: Observer: Temperature: Pressure: Re1. Hum.: , Cs(Cs)- :t AMsw(Msw)- Ps-... Open at page → 8 Page 8 Appendix Transposition Data Sheet for Equal-Arm Balance (Option B) Test No. : Sheet No.: Date: Item Identification: Balance: Standard Identification: Observer: Temperature: Pressure: ReL. Hum.: , Cs(Cs)- :! AMsw(Msw)- Ps... Open at page → 9 Page 9 Appendix Transposition Data Sheet for Equal-Arm Balance (Option A) Test No.: 135 Sheet No.: 1 Date:8/26/86 Item Identification: 1000 lb No. 4211 Balance: Russell Standard Identification: #11 and #22 Observer: HO Temperat... Open at page → 10 Page 10 ANt + ANt- ANt - ANt 81 82 xi x2 01 - 02 . ( ~-~+ 2 + 2 3.625 + 3.625 . 3.617 - 3,612 Ox - .0047 + 2 Cz - .0047 + .0105 + .000659 Cz - 0.015859 lb Unertainty - ta + U8 AMsw ) 03 - 02 + 20.35 - 19.75 2 Degrees of freedom... Open at page →