異常 and 正常: checks, warnings, normal operation and a normal range
Compare checking a model and reading a warning with an inspection finding normal operation and body temperature returning to a normal range.
A movement check and a warning with 異常
「模型の動きに異常がないか確かめた。」 (We checked the model for any abnormal movement.) 異常 (いじょう) means abnormality. The model was checked for any abnormal movement. 異常がないか identifies what was checked; the sentence does not itself state a final finding of no abnormality.
「警告灯が機械の異常を知らせている。」 (The warning light indicates a problem with the machine.) The warning light indicates a problem with the machine. Read 警告灯が with 異常を知らせている to identify the indicator and what it signals. No specific faulty part or cause is supplied.
Normal operation and a normal range with 正常
「点検の結果、機械は正常に動いていた。」 (The inspection found the machine operating normally.) 正常 (せいじょう) means normal. The inspection found the machine operating normally. It discovered that state; it is not described as causing the machine to become normal.
「体温が正常な範囲に戻ったので安心した。」 (I was relieved when my body temperature returned to the normal range.) The speaker was relieved when body temperature returned to the normal range. 正常な範囲 identifies the range it returned to. No numerical range or complete recovery is supplied.
Distinguish a check from a stated finding
The model sentence reports a check for abnormality, and the warning-light sentence reports an indication of a problem. The inspection sentence supplies a finding of normal operation, while the temperature sentence supplies a return to a normal range and relief.
Read what 異常 or 正常 concerns alongside the status of the check or finding. A movement check, a warning, discovered normal operation and a changed temperature range each supply different information.
How do the check for abnormality and the finding of normal operation differ in the 異常 and 正常 examples?
Show the answer and why
The first reports a check without a final finding about abnormality. The second reports that the inspection found normal operation. It does not say that the inspection caused the machine to operate normally.