Level 2 sleep study

Hi,
I’m fairly new to this process/journey.
I’ve hired an APAP machine. It was a SleepStyle from F&P. I don’t have a diagnosis as yet. In my country there are a number of routes you can take.
The machine has made a noticeable difference to my sleep. So I’m sure it is assisting my sleep. The service that has hired the machine also allows customers to hire a diagnostic machine. This is known as a level 2 study. No specialist is present. The machine takes blood/oxygen levels but doesn’t have the brainwave sensors. So it’s not as comprehensive as other professional studies.
My question is this, should I hire the assessment machine after using the APAP machine for a month, or wait for a cpl of weeks. I’m wondering if the use of the machine may have changed my symptoms such that they’ll effect the result.

I'm a little confused with your terminology, but using the APAP will not change your symptoms. Use of CPAP/APAP does not cure your symptoms. The machine is like eyeglasses....it helps while you use it, but when you stop using it all your original symptoms return. It treats, but does not cure.

Are you wanting to do the home sleep study while using the machine or when not using the machine?
What is your goal for doing the home study?

In the USA a level 2 home sleep study does check for actual sleep stages using leads to the head or brainwave sensors...level 3 or 4 sleep studies don't do that. It is entirely possible that in your country the types of home studies available are named/numbered differently.
http://freecpapadvice.com/home-sleep-tests

It sounds different here in Australia. We have level 1-3. Level 3 does not involve a medical professional and is a breathing device strapped to the chest, which has a small tube that runs to the nose, and a small device attached to the index finger, which I assume record pulse and possibly O2 levels as well.
I am keen to establish if I have some OSA symptoms without doing a medical diagnostic study. Hard to explain but due to personal reasons I would like to avoid that path for the time being. I have returned the machine and hired the resmed device for the night. It will record my sleep patterns/behaviours and then be available for the dtaff to download from the device and check in the morning.

Ah I can see the confusion caused by my original post.
I am talking about two different machines. I have hired a CPAP/APAP machine for a month without a diagnosis. It’s available to test for a month or two. Then the hire costs are deducted off the cost of a purchase should you then make one. Their prices are very good.
I have completed the one months test hire and found the machine to be aiding my sleep. I actually feel good about going to bed, and good when I wake up. I have suspected I have some OSA symptoms for a while now. I haven’t had a medical diagnosis and I would like to avoid that at this stage. However it may be unavoidable eventually. But I would like to be as educated about this process and my symptoms as much as possible before going down the formal medical path.
I have the opportunity to hire a diagnostic machine to carry out a level 3 assessment. This does not involve medical professionals and is carried out using a small device strapped to the chest, which has a cpl of small tubes that go to the nostrils, and a sensor attached to the finger. It’s called an ApneaLink Air made by Resmed.
My OP was about whether it would be appropriate to wait a period of nights after using a CPAP machine before using the diagnostic machine or could I use it straight away (obviously not at the same time as the CPAP machine). The staff advised that if I have OSA then my symptoms will return immediately and so I can use the diagnostic machine the following night. I plan to do so tonight after returning the hired CPAP machine today.
I th my symptoms are mild.

I have not had a formal sleep study done. Whilst that may seem like an obvious first step, I wanted to do some investigating of my own before I opened up what could be a can of worms for me.
I hired a F&P SleepStyle APAP machine for a month. The company (CPAP Direct) here in Australia let you hire a machine without a prescription. You sign a waiver and pay about $200 for the month. This cost comes off the purchase of any machine you may decide to buy later. You can do this for a max of 2 months.
After a few adjustments in the setting and a change of masks, I found that a constant pressure of 5 and the Resmed N20 Nasal mask suited me and I could sleep very well. I found the machine improved my sleep. Not enormously but enough to notice the difference and feel a benefit. Upon completion of the first months hire, I decided that before I forked out the cash, I should hire their diagnosis machine for a night. It costs $50.
I did, and I am surprised to learn I have an AHI of 3.1. My O2 saturation % went as low as 90, with a baseline of 98.
It says after 7 hrs sleep I had 1 apnea event and 15 Hypopnoeas.
My question is, is this diagnosis reliable? Should I consider myself not suffering from OSA/CSA? Is the Resmed ApneaLink Air sufficiently comprehensive enough to diagnose or could it have missed something? Should I hire it again in a month?
Whilst I did not feel I was being “sold” or pressure to buy at all, I was told that if I feel some positive effect from the machine, that I could still consider purchasing one.

It is really good to know that you are getting the benefits of using APAP. I also use CPAP to get the cure for sleep apnea. I have not done any study yet, after doctor prescription I am using this. But I will also do some study and observation of my sleeping status, to know how effectively my CPAP machine is working.