About monthly report

This page explains the "monthly report", which is a data collection that summarizes the measurement results for one month in the form of a table for each measurement station and measurement item.

In the constant monitoring of air pollution, for pollutants such as nitrogen dioxide and suspended particulate matter is calculated every hour, which is the average concentration of one hour every hour.

Then, the measurement results at each measuring station are tabulated every month by measuring station and measurement item, and a table called "monthly report", which is a data collection that describes the one-hour value for one month, is created ( Print).

The hourly values listed in the monthly report are the most basic measurements for constant monitoring.
The daily average, which is the average value of 24 hours a day, is calculated from the 1 hour value.

In addition, monthly and annual statistical values, such as monthly averages and average annual values are calculated from one hourly values for substances other than PM2.5. (* Only PM2.5 is calculated from the daily average.)

Then, based on the measured values of the monthly report for the 12 months from April to March of the following year, an "annual report" is created with annual measurement results (annual average value, etc.).

The monthly report is a book that lists the hourly value for one month on a sheet of paper (about B4 horizontal) for each measurement year month, measurement station, and measurement item. Statistical values are also described.

The layout of the general monthly report is divided into the top title and the data part below (table), as shown in the example below.

The top title shows the measurement date, the name of the measuring station, the measurement items, and their units.

In the data part at the bottom, the value of the 1-hour value for 31 days x 24 hours (if the number of days in the month is 31 days) are described in the form of a table.

When creating a monthly report, the data including the decimal point has a large number of characters, so if the data is lined up for 24 hours, the table may not be able to fit the paper width (such as B4). Also, if there are many zero numbers in the table with zero, such as 0.001 ppm, it will be difficult to compare the size of the numbers at first glance.

For this reason, in the monthly report, it is common to treat a number that contains the decimal point is converted to an integer by 10, 100 times, or 1000 times, depending on how many digits after the decimal point is, and converted to an integer (with fewer characters).

For example, the concentration of nitrogen dioxide (NO2) is generally displayed in three decimal places (5 characters in total) such as 0.123 ppm, using units of ppm, but in the case of monthly reports, It is displayed in 123ppb and 3 digits (3 characters) using ppb, which is a unit that multiplied the value of ppm multiplied by 1000 times instead of ppm.