Assessment of Strength Compliance with Standards for Tanzania Eucalyptus Wood Poles Treated with Copper-Chromium-Arsenic Compounds

2007 ◽  
Vol 30 (2) ◽  
pp. 110-118
Author(s):  
Alex Lyatonga Mrema
Keyword(s):  
South African ◽  
Power Transmission ◽  
Quality Level ◽  
Arsenic Compounds ◽  
Loading Test ◽  
Eucalyptus Wood ◽  
Acceptable Quality ◽  
Average Modulus ◽  
Acceptable Quality Level ◽  
Copper Chromium

Samples of copper-chromium arsenic compounds (CCA) treated Eucalyptus poles for power transmission were sampledfrom a lot following Military Standard MIL-STD 105D, Single sampling, Tightened Inspection, Acceptable Quality Level(AQL) of 4 as provided for in the South African Standard SABS 754:1994 from lots containing 151-500 poles. Sampleswere randomly selected from a lot. Maximum fiber stresses were evaluated taking into account the actual taper in eachpole. The cantilever loading test was performed on the samples following SABS 754:1994. It was found out that theaverage taper for the poles was smaller than that assumed in the standard due to the different pole growthcharacteristics and environment in Tanzania and that the average modulus of elasticity obtained for the poles was lowerthan the average assumed in SABS 754:1994. The poles also showed excessive deflections at working loads. It isrecommended to the Tanzania Bureau of Standards that although SABS 754:1994 is meant to be used for eucalyptuspoles grown in Southern Africa south of the Sahara that are treated with creosote or CCA there is a need to review it totake into account the actual characteristics of the poles grown in Tanzania where they are normally grown in highlandareas with higher rainfall and colder climates.

scholarly journals Mejoramiento de la calidad en la recepción de materias primas, mediante la implementación de un plan de muestreo por variables

2020 ◽  
pp. 19-31
Author(s):  
Fernando Hernández-Benito ◽  
Martín González-Sóbal ◽  
Montserrat Gómez-Márquez ◽  
Miguel Ángel Solís-Jiménez
Keyword(s):  
Sampling Plan ◽  
Raw Material ◽  
Quality Level ◽  
Current State ◽  
Acceptable Quality ◽  
Inspection Process ◽  
Acceptable Quality Level ◽  
Action Strategies ◽  
Process Methodology

Objective: To guarantee the adequate inspection of raw material and packaging material by the inspection-receipt area by implementing an effective sampling plan that allows reducing the percentage of defective raw material and its impact on the production process. Methodology: It is based on the continuous improvement cycle (PHVA) within which a diagnosis is made to determine the current state of the inspection process, which will allow defining new action strategies aimed at standardizing the inspection process, through the implementation of a sampling plan by variables based on the MIL-STD 414 standard, once implemented, this process is documented, at the same time the integration of suppliers is carried out, through periodic evaluations in order to know the dynamics of the new inspection process and work only with those suppliers committed to the quality of their inputs. Contribution: Reduction of the percentage of defective raw material, from 21% to 13%, which means an acceptable quality level of the materials of 87%.

scholarly journals Optimal Designing of Variables Chain Sampling Plan by Minimizing the Average Sample Number

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
S. Balamurali ◽  
M. Usha
Keyword(s):  
Operating Characteristic ◽  
Characteristic Curve ◽  
Sampling Plan ◽  
Quality Level ◽  
Sample Number ◽  
Acceptable Quality ◽  
Acceptable Quality Level ◽  
Limiting Quality Level ◽  
Optimal Designing ◽  
Average Sample

We investigate the optimal designing of chain sampling plan for the application of normally distributed quality characteristics. The chain sampling plan is one of the conditional sampling procedures and this plan under variables inspection will be useful when testing is costly and destructive. The advantages of this proposed variables plan over variables single sampling plan and variables double sampling plan are discussed. Tables are also constructed for the selection of optimal parameters of known and unknown standard deviation variables chain sampling plan for specified two points on the operating characteristic curve, namely, the acceptable quality level and the limiting quality level, along with the producer’s and consumer’s risks. The optimization problem is formulated as a nonlinear programming where the objective function to be minimized is the average sample number and the constraints are related to lot acceptance probabilities at acceptable quality level and limiting quality level under the operating characteristic curve.

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