Thread size for temperature sensor on water outlet 1HZ

[EsbenDenmark]

On the water outlet there is a plug I want to use for a water Temperature sensor. I think the bolt not is 16mm. But what is the thread size?
1.5mm?

I am thinking I would install a KUS water pemperatur sensor

 

[svsisu]

You should get further verification, but I believe it is M16x1.5.

 

[Themcfarland]

Here are some screenshots I made when I was searching this