Digital identifier

Figure 1 Average Error Data for Each Site. Average error was calculated for each site as described in Materials and Methods. Numbers below each bar correspond to 4 digit identifier codes provides by each respondent. The type of derivatization chemistry used is indicated by the shading of each bar. Note the different scales on the two plots.

To round to three digits, identify the third significant figure, in this case 1, and then look at the number to its right, in this case 5. 

Airline tickets have 15-digit identification numbers associated with them. The first 14 digits identify the ticket and the 15th (the last one) is the check digit. 

Each MSDS has a unique number assigned to it, known as a P-Number. The P-Number is a six-digit identifier (five digits and one decimal place) that can be used to track a specific MSDS by the type of chemical that it represents and the manufacturer or supplier of that product. When there are numerous manufacturers or suppliers of the same product, the decimal place differentiates them. An example would be isopropyl alcohol. The first five digits for all isopropyl alcohols are 00518. However, since it is a fairly common chemical, it is purchased from a number of different sources. The P-Number for isopropyl alcohol from Allied Chemical Company is 00518.1 the P-Number for isopropyl alcohol from Ashland Chemical is 00518.3. When there are more than nine manufacturers or suppliers, two decimal digits are used to continue this logic. 

Three digits identify the specific chemical group, the modification or use class, and the grade by viscosity or... 

The first two numbers in the five digit identifier can identify a type of system or a section of the process. The final three numbers identify the specific piece of equipment. 

Line numbers are often of the form 00"-XX-00000-X0X-X0". The first two numbers are the nominal line diameter. The next two letters show the type of process stream, such as PG for process gas. The next five digits identify the process type or area and the number of the line. The next three digits (XOX) indicate the pipe specification, and the last two digits provide information about the type of insulation. Hence the line number 12"-PG-30012-A1A-P1" tells the reader that the line has nominal diameter of 12 inches, it carries process gas, it is located in Section 30 of the facility, the line number is 012, the specification is AlA, and the line is provided with 1 inch of personnel protection insulation. 

The first digit indicates the alloy group. The second and third digits identify the specific aluminum alloy. The fourth digit indicates the product form ... 

The last two digits identify the aluminum alloy or indicate the alloy purity. In the alloys of the Ixxx series, the last two digits... 

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