Lua - Oil Tank Monitor query

[stuiow]

Hi all,
I've finally managed to fix my rtl_433 issue and its now getting its distance and temperature reading from my oil tank.

I've grabbed the LUA script from here ahttp://www.domoticz.com/wiki/Lua_-_Oil_ ... ticz_Setup

I've modified it with my tank dimensions and synced the collected data with some created sensors with the same names given in the script (Oil tank temp and Oil tank sensor).

What i have a query about is the next bit

-- Output devices: Percentage full, volume.
pct_sensor = 'Oil tank'
pct_sensor_id = 4
volume_sensor = 'Oil'
volume_sensor_id = 5

Where do i get the ****_sensor_id's from, as above, its quoted as 4 and 5.
Are these the IDX values as seen in the devices screen?
https://www.dropbox.com/s/ygdqicogz3iud ... .PNG?dl=0]
Any feedback would be appreciated.
Cheers