All petrol vehicles fitted with cats from 92 on get whats called the BET test ( Basic Emissions Test) limits are as follows.
Co. 0.200 max
Hc 200 max
Lamba 0.97 - 1.03
If car passes that deemed all good.
If it fails that then it will get a full catalyst test this will be model and year specific the tester analyser will have a database with a lot of cars in it ( all zed models are in all of ours) .
If the specific make and model there is a set of default limits set down in the manual ( flow chart on emissions section of mot manual) to determine the limit for that year .
There is the odd exception but nothing sort of mainstream.
Based on testing a fair few petrol cars over the years if the engine cat and lambda in good condition it will pass the bet test with ease.
This is a set of figures from a single vanos 2.8 ( 97 single cat and lambda)
Was doing some brakes on it for an upcoming mot thought while had it would check emissions car wasn't fully warmed up when checked still passed no problem.
Edit.
Sorry in answer to original questions mot analyser will have a set of basic questions after reg input to determine the type of emissions ( eg petrol ,diesel cat ,non cat etc ) the machine will apply the limits and type based in this.
Stephen.