A digital radiometer that reads ultraviolet output in microwatts per square centimetre. Its job is to tell you when a UVB lamp is spent — fluorescent and mercury vapour lamps keep producing visible light long after their UVB has faded, so without a meter the only guide is the calendar, and calendars are conservative by design.
What it does
- Reads UV output in µW/cm².
- Tracks decay over time — compare today's reading with the one you took when the lamp was new.
- 9V battery — included and fitted, with a low-battery indicator.
An important limitation
These readings are relative, not absolute. Different lamp types have different spectral outputs, so a µW/cm² figure from a T5 tube cannot be compared with one from a mercury vapour lamp. Use it to track a single lamp against itself over time, taking readings from a consistent distance and letting the lamp warm up for five minutes first. If you want to set a basking-zone UV Index and compare across lamp types, the tool for that is the UVB Index Meter.
Lamps in Reptile Heating & Lighting.
