Zeal Mason's Type Make Wet and Dry Bulb Hygrometer

Best performance

Good

No murcury reading is visible. Too difficult for reading

Shows correct temperature, buy blue color pack plz don't buy purple color pack, because purple one shows wrong temperature.

Old technology

The glass is formed in a way that the red liquid is visible in an extremely thin line and only from a very specific angle of viewing. I routinely have to use my phone to take a pic and then zoom in on the photo to see the reading. I do still recommend this for its importance in determining how bad the wet bulb generator can get. That is the temp to watch carefully as climate disruption gains intensity.

Very good

Nice