Every number in a technical article has to be traceable back to its source. This sounds like common sense, but in practice the thing that goes wrong most often is not deliberate invention but distortion in the retelling: a range is written as a single value, an approximate value is written as an exact one, and a figure that only holds under specific conditions is treated as a general one. When we write an article we divide the checking into several passes and go through them one by one before publication.
The first pass: which document the number comes from
Parameters come from two sources: the rated values given on the equipment drawings and the nameplate, and the measured values given in the test records. The two are different in nature and should be written differently in an article. The treatment flow rate of the ZYD-100, 6000 L/h, is a rated value; the working vacuum, -0.08 ~ -0.0999 MPa, is a working range; the ultimate vacuum, ≤5 Pa, is an upper limit; the water content ≤3 ppm (GB/T 7600), the gas content ≤0.01% (GB/T 423), the breakdown voltage ≥65 kV (GB/T 507) and the cleanliness NAS 1638 class 5 are figures that carry conditions. The total power 72 + 5 kW, the dimensions 1200×1400×1800 mm and the weight of the machine, approx. 720 kg, are the overall machine parameters.
The question to ask when checking is: which machine does this number come from, which version of the document, and what date. What is written down should be the line in a specific document, not something remembered from an impression.
The second pass: whether ranges and approximate values have been rewritten
The temperature control range 45–80 °C is a range, and the upper limit pulled down to 70 °C when the water content is high is a limit under another condition; the two cannot be merged into a maximum of 80 °C. The approx. in a weight of approx. 720 kg must not be dropped, because without that word the reader takes it as an exact value. The filtration accuracy ≤1 μm is an upper limit; it does not mean that 1 μm particles are filtered out, and the two statements do not mean the same thing in practice. Wherever an article writes approx., not exceeding or not less than, it has to be checked word for word against the original document.
The third pass: whether the standard numbers and the methods go with the figures
A figure cannot exist on its own without the standard number. When the water content is written as 3 ppm, GB/T 7600 goes with it; when the breakdown voltage is written as 65 kV, GB/T 507 goes with it; when the gas content is written as 0.01%, GB/T 423 goes with it; and when the cleanliness is written as class 5, NAS 1638 goes with it. Cleanliness also has another coding system in ISO 4406, and the two systems cannot be converted into one another on paper. The same attention is needed for things outside the test figures: the oil source, the certification qualifications, client names, transaction amounts, award records and industry rankings are not parameters that can be written into an article.
| Item checked | Document it comes from | The usual mistake |
|---|---|---|
| Overall machine parameters | The equipment drawings and the nameplate | Writing the measured value of one particular machine as a model parameter |
| Ranges and upper limits | The technical agreement and the manual | Writing the range of 45–80 °C as the single value 80 °C |
| Approximate values | The test records and the drawings | Writing approx. 720 kg as 720 kg |
| Test figures | The corresponding standard text | Writing the value only, without the GB/T or NAS 1638 |
| Model and configuration | The order confirmation | Treating a special configuration from one project as the standard configuration |
| The two language versions | The Chinese-English comparison table | The English version turning a range into a single value |
The fourth pass: after the Chinese version is written, check the English version again
When the Chinese and the English versions are published together, the figures themselves are what distort most easily: the temperature range is written as two numbers instead of one range in the English version, the hyphen in a model code is changed to another symbol, and the units are converted into imperial ones. When checking, take the Chinese version as the reference and compare item by item: the numbers, the units, the model codes, the dimensions and the standard numbers are copied as they are, and only the labels in front of them are translated.
- Before publication, list every number that appears in the article, mark the source of each one and confirm that no number has been added that is not in the original document.
- For statements with approx., not exceeding or not less than, check the qualifying word together with the value instead of looking at the value on its own.
- Everywhere a standard number is written, confirm once more that it has not been paired with the wrong figure.
- Check the English version item by item against the Chinese-English comparison table; the ranges, the units, the model codes, the dimensions and the standard numbers cannot be changed.
- If a number turns out to be wrong after publication, mark the line in the original document at the same time as the article is corrected, so the same mistake is not made again.
The numbers in an article are not there to look professional; they are there for people to act on. Each one has to point back to where it came from.
