該当 and 相当: matching an item, considerable time and qualifying experience
Distinguish matching requirements or a listed item from considerable repair time and experience qualifying under an application requirement.
Checking requirements and matching an item with 該当
「応募条件に該当するか事前に確認してください。」 (Please check in advance whether you meet the application requirements.) 該当 (がいとう) means applicability. The sentence asks for an advance check of whether the application requirements are met. It supplies neither a confirmed match nor a completed application.
「一覧の中に自分の症状に該当する項目はなかった。」 (There was no item on the list that matched my symptoms.) There was no listed item matching the speaker's symptoms. 該当する項目 concerns a matching item on that list; its absence does not establish the absence of symptoms or a diagnosis.
Considerable time and qualifying experience with 相当
「古い倉庫の修理には相当な時間がかかった。」 (Repairing the old warehouse took considerable time.) 相当 (そうとう) means considerable or corresponding. 相当な時間 expresses the considerable time taken to repair the old warehouse, without an exact duration.
「この経験は応募条件の実務経験に相当する。」 (This experience qualifies as practical experience under the application requirements.) The experience qualifies as practical experience under the application requirements. 相当する concerns this correspondence, without reporting an accepted application or a hiring outcome.
Identify a match, an amount or a qualifying relation
The 該当 examples concern checking a match with requirements and finding no matching item for symptoms. The 相当 examples concern considerable time and experience qualifying under a requirement. Identify whether the sentence concerns a match, an amount or a corresponding qualification.
Keep the requested advance check separate from the reported absence of a matching item. Considerable repair time and qualifying experience likewise supply different information; meeting a requirement does not itself report application or hiring completion.
What do the absence of a symptom-matching 該当 item and repairs taking 相当な時間 describe?
Show the answer and why
The first describes no item on the list matching the speaker's symptoms. The second describes considerable time taken to repair the warehouse. Neither a diagnosis or absence of symptoms nor an exact duration is supplied.