Good Ruler easy to place in your tool bag. That’s what I carry with me.
Do I need:
gas sniffer
CO2 analyzer
Are these “nice to have” items that are beyond the scope of inspections?
Nice to have, beyond the scope.
Inspector outlet has a microwave tester for about $5.
Both will need periodic calibration or you could be getting false readings just remember that if you are going to spend the money. From what I can tell a good CO2 detector is around $800. (I have looked into them also and don’t plan on getting either until I can justify it with inspections amounts)
What Frank said…