BASIS PELAPORAN HASIL ANALISA

Basis Pelaporan Hasil Analisa Basis Pelaporan Hasil Analisa ARB (As Received Basis ) ==> Basis Pelaporan Hasil Analisa sebagaimana adanya di Alam ADB ( As Determined Basis) ==> Basis pelaporan atas analisa yang di kondisikan di Laboratorium DB (Dry basis) ===> Basis pelaporan hasil Analisa dengan asusmsi Kering Total DAF (Dry Ash Free Basis) ===> Basis Pelaporan hasil Analisa dengan Asusmsi Kering Total dan tanpa Abu Perlu di perhatikan Nilai Parameter dalam ARB ataupun ADB merupakan Nilai Parameter pada KOndisi Moisture nya Masing masing Membandingkan Hasil Analisa ARB harus di dasarkan pada nilai Total Moisture (TM ) yang sama Membandingkan Hasil Analisa ADB harus di dasarkan pada nilai Moisture (M ) yang sama Hasil Analisa pada DB ataupun DAF adalah RElatif Constant dan Typical untuk setiap Jenis batubara Hasil Analisa adalah Bersifat Relatif dan Bukan Absolut Sifat Relatif di akibatkan karena adanya perbedaan Kondisi Alat,kondisi Laboratorium dan ketrampilan Analis yang melakukan Analisa Repeatability ==> Perbedaan Hasil analisa yang di bolehkan apabila sample yang sama di analisa dengan alat yang sama pada Laboratorium yang sama tetapi Analis berbeda Reproducibility ===> Perbedaan Hasil analisa yang di bolehkan apabila sample yang sama di analisa dengan Alat , Laboratorium dan Analis yang berbeda Reproducibility ASTM TM 0.65 % VM 1 % Ash 0.32 % TS 0.1 %

FORMULA PERHITUNGAN DRAFT SURVEY

DRAFT SURVEY MOTHER VESSEL

Introduction to Draft Survey

The first question we need to answer is : Why is a draft Survey ?
This is simply a technique for assesing the weight of bulk cargoes on board a vessel by reading the vessel's draft marks before and after loading

The prosedure also accounts for any other change in the weight on board,the accuracy of a draft survey largely depends on the experience and care taken by the surveyor concerned

The technique of draft survey is based on Archimedes prinsiple.This States that

A vessel when freely floating in water will displace a weight of water equal to its own weight

in the following sections of this manual , details will be given regarding the prosedures to be followed but before going any further , it is essential that you understand the following three point :

1 The weight of water displaced by a loaded vessel is not only due to the cargo but also includes :

• the weight of the vessel in light condition.This is the vessel itself and the equipment required for sailing
• The deductible liquids on board These are

1. The ballast water required for stability
2. the fresh water for drinking and cooling
3. the bunker contents - that is the fuel and lubricating oils

2 Since seawater (density 1.025) is heavier than fresh water (density 1.000) the volume of water displaced by an object floating in salt water is smaller than the volume of water displaced in fresh water

3 the vessel's documents which are required to carryout a draft survey are based on:

• the vessel floating in water of certain density
• the vessel being on even keel.That is with the same draft reading forward and after
• the vessel being upright .that is without list and with the same midships draft on port and starboard sides
• Unfortunately, such ideal conditions are rarely encountered and in practice certain corrections have to be applied