Siinä tapauksessa, että irtaimisto on märkää, ottakaa valokuvia viipymättä.

Both can mean if, but siinä tapauksessa, että is more formal and bureaucratic. It is common in instructions, legal language, insurance texts, and official notices.

So:

• Jos irtaimisto on märkää, ottakaa valokuvia heti. = simpler, more everyday
• Siinä tapauksessa, että irtaimisto on märkää, ottakaa valokuvia viipymättä. = more official and formal

A natural English equivalent here is In the event that the contents are wet, take photographs without delay.

Together, siinä tapauksessa literally means in that case.

The forms are:

• siinä = in that / in it, the inessive form of se
• tapauksessa = in the case, the inessive singular of tapaus

So the structure is literally something like in that case, that..., although in natural English you would translate the whole expression as in the event that or simply if.

Here että introduces the clause irtaimisto on märkää. After siinä tapauksessa, Finnish often uses että to mean that / if it is the case that.

So:

• siinä tapauksessa, että... = in the event that...

This is a fixed and very common formal pattern. Even though English often drops that in this kind of sentence, Finnish keeps että.

Irtaimisto is a fairly formal word meaning movable property, contents, belongings, or sometimes furnishings, depending on context.

It does not usually refer to one single object. It is a collective singular noun: one grammatical singular word that refers to a group or mass of movable items.

In practical contexts such as insurance or water damage, irtaimisto often means things like:

• furniture
• household items
• personal belongings
• loose contents of a room or building

So even though the word is singular in form, its meaning is broader than one item.

This is because Finnish often uses the partitive singular in predicate adjectives when the subject is understood as a mass, substance, or collective whole.

So:

• vesi on kylmää = the water is cold
• puuro on kuumaa = the porridge is hot
• irtaimisto on märkää = the contents / movable property is wet

Here irtaimisto is being treated like a collective mass rather than one clearly bounded item, so märkää sounds natural.

If you were talking about one specific countable thing, you would normally use nominative:

• matto on märkä = the carpet is wet

Ottakaa is the imperative form of ottaa for:

• you plural
• or formal you singular

So it means take!

Examples:

• ota = take! (to one person, informal)
• ottakaa = take! (to several people, or politely/formally to one person)

In instructions and notices, ottakaa is very common because the reader is either a group of people or is being addressed politely.

Valokuvia is the partitive plural of valokuva. Here it means photographs / some photographs in a general, indefinite sense.

That is natural with the verb ottaa when the object is not a specific complete set. The instruction is basically telling you to take however many photos are needed.

Compare:

• ottakaa valokuvia = take photographs / take some photos
• ottakaa valokuvat = take the photos / take the specific set of photos

So valokuvia fits the meaning better here because the sentence is not talking about already known, specific photos.

Yes. Ottaa valokuva or ottaa valokuvia is the normal Finnish way to say to take a photo / to take photos.

Literally, ottaa means to take, but this is a standard collocation, just like in English.

Examples:

• Otin valokuvan. = I took a photo.
• Otin valokuvia. = I took photos.

So there is nothing unusual about that part of the sentence.

Viipymättä means without delay, immediately, or promptly. It is a formal word, very common in official instructions.

It comes from the verb viipyä, which means to delay, to stay, or to linger, depending on context. The ending -matta / -mättä gives the idea without doing something.

So viipymättä is literally something like without delaying.

A less formal alternative would be:

• heti = immediately
• välittömästi = immediately, at once

But viipymättä sounds especially official and instruction-like.

Finnish uses commas before many subordinate clauses more regularly than English does.

In this sentence:

• Siinä tapauksessa, että irtaimisto on märkää, = subordinate clause / condition
• ottakaa valokuvia viipymättä. = main clause

So the commas help mark the clause boundaries:

1. before the että clause
2. after the whole opening condition, before the main instruction

That punctuation is normal Finnish style for this kind of sentence.