البطانة في غرفة القياس.

It can be a complete sentence in Arabic.

It is a nominal sentence:

• البطانة = the subject
• في غرفة القياس = the predicate, as a prepositional phrase

So the structure is basically:

• البطانة = the lining
• في غرفة القياس = in the measurement room

In natural English, you would usually translate it with is:

• The lining is in the measurement room.

Because in Arabic, the present-tense verb to be is usually not written or spoken in sentences like this.

So Arabic says:

• البطانة في غرفة القياس literally:
• the lining in the measurement room

But the meaning is:

• The lining is in the measurement room.

If you wanted a past meaning, Arabic would normally use a verb such as كان:

• كانت البطانة في غرفة القياس = The lining was in the measurement room.

This is because غرفة القياس is an iḍāfa construction, often called a construct phrase.

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun can make the whole phrase definite

So:

• غرفة القياس = the measurement room

Even though غرفة has no الـ, the whole phrase is definite because القياس is definite.

Compare:

• غرفة قياس = a measurement room or measurement room
• غرفة القياس = the measurement room

Meanwhile, البطانة is separately definite because it has الـ.

It is an iḍāfa phrase:

• غرفة = room
• القياس = the measurement / measuring

Together:

• غرفة القياس = the room of measurement
• more naturally in English: the measurement room

This is a very common Arabic pattern:

• باب البيت = the door of the house
• مدير المدرسة = the principal of the school
• غرفة القياس = the measurement room

Because of the ة at the end, called tāʾ marbūṭa.

When a word like غرفة stands alone in pause, it is usually pronounced like:

• ghurfah

But when it is connected grammatically, especially in an iḍāfa or with case endings, the t sound appears:

• ghurfatu
• ghurfati
• ghurfat al-qiyās

So in this sentence, because it comes after في and is part of غرفة القياس, it is not just ghurfah in careful reading. It becomes something like:

• ghurfati l-qiyāsi in full formal pronunciation

In fully vocalized formal Arabic, the sentence would be:

البطانةُ في غرفةِ القياسِ

Here is why:

• البطانةُ is nominative because it is the subject of the nominal sentence
• في is a preposition
• غرفةِ is genitive because it comes after في
• القياسِ is also genitive because it is the second noun in an iḍāfa

So the grammatical pattern is:

• البطانةُ = subject, nominative
• في غرفةِ القياسِ = prepositional phrase, with genitive nouns

In normal Arabic writing, these short vowels are usually not written, so learners have to infer them from grammar.

It is pronounced al-qiyās.

The ل in الـ does not assimilate here, because ق is a moon letter, not a sun letter.

So:

• القياس = al-qiyās

Compare that with a sun-letter example:

• الشمس = ash-shams, not al-shams

So for your sentence, a careful pronunciation would be roughly:

• al-biṭānatu fī ghurfati l-qiyāsi

And in a more pause-based learner pronunciation, you might hear something closer to:

• al-biṭānah fī ghurfat al-qiyās

القياس is a verbal noun or maṣdar from the verb قاسَ meaning to measure.

So:

• قاس = he measured
• قياس = measuring / measurement

In this sentence, القياس means measurement and helps form the noun phrase:

• غرفة القياس = measurement room

This is very common in Arabic: a maṣdar is often used the way English uses nouns like measurement, study, training, or inspection.

The ة is usually a sign that the noun is feminine.

So both:

• البطانة
• غرفة

are grammatically feminine nouns.

This affects things like:

• adjective agreement
• pronouns
• verb agreement in some contexts

It also affects pronunciation:

• in pause, ة often sounds like -a or -ah
• in connected grammar, it often shows a t sound

So:

• غرفة by itself: ghurfah
• غرفة القياس: ghurfat al-qiyās / ghurfati l-qiyāsi

The word order is very normal for Arabic.

Arabic often begins a nominal sentence with the thing being talked about:

• البطانة = what the sentence is about

Then it gives information about it:

• في غرفة القياس = where it is

So the sentence is structured like:

• The lining
  • is in the measurement room

This is one of the most common and useful sentence patterns in Arabic:

• الكتاب على الطاولة = The book is on the table.
• المدير في المكتب = The المدير is in the office.
• البطانة في غرفة القياس = The lining is in the measurement room.