I am looking for some guidance on getting tools for checking and balancing radiators after my heat pump install. I have read the Radiator Balancing - is there an idiots guide? and related threads. Whilst thread offers a lot on process and what to look for it looks like everyone is using their own tools and approach. sofar I have done some prelim balancing with guidance from Design Temperatures and Radiator Sizing. Just used lock shield turning and touch-feel method to check the radiators . I am hoping to get a more accurate measuring tool to focus on checking and tuning the radiator deltas (5-7) for each of the radiators. The tools I have checked so far are
I am looking for low cost tool, and only interested in checking if the deltas across the radiators are decent. Do not mind if the accuracy of the flow temperatures (actual values) are not that great as long as it is consistent.?
I am aware that there are expensive options, testo and fieldpiece, I can go there (can get 1) if the none of the low cost ones are no good for delta checking? Any advice?
I’ve used cheap k-type clamp on pipe thermometers from Amazon. I clamp to the flow and return on either side of the radiator. I think they’ll only work well on copper pipe, if you have a different pipe type, an ir or thermal image solution might be better.
They aren’t massively accurate but sufficient for a diyer I think. I found them more reliable than an ir thermometer.
Here’s a link to a cheap set similar to what I have.
Good tip. I came across that one but was worried about the lack of reviews. I believe the part that connects into the radiator might be copper. Rest is covered in some sort of tube sheathing.
Wemos D1 Mini v4 running ESPhome.
A couple of DS18B20 temp probes.
Home Assistant to log the data.
You could be under way here and still have change from £20.
and touch-feel method 
to check the radiators 
. I am hoping to get a more accurate measuring tool to focus on checking and tuning the radiator deltas (5-7) for each of the radiators. The tools I have checked so far are