Dwyer® Red Gage Fluid, A-101, 1 oz Bottle, .826 Specific Gravity

Exactly what was needed to refill my Dwyer manometer. I thought my Radon mitigation fan was failing as the manometer reading kept falling over time. Adding (follow instructions for your meter) fluid to the meter and zeroing it correctly resulted in a good reading and showed my fan was still in good shape. Excellent!

This is pricey but it's the exact match

I'll probably never need this again but it got my manometer back in action after years of non use.

The bottle did not come with a tip extension as shown in the product photo. This made it impossible to fill the manometer in an installed position without jury rigging some other way to fill it. The product itself is exactly what I ordered other than that.

My radon reduction system wasn't working so I had to replace the fan. But then I realized I didn't have enough fluid in it so I bought this fluid and it works perfect.

Hard to find fluid additive but exactly what the gauge required!

This gage fluid is widely used in Dwyer pressure gauges used for radon mitigation systems. Over a period of years, the level goes down and it needs to be refilled. You can do it yourself! Just disconnect the tubing, add this fluid through the fill port, and adjust the knob to set the zero level. Then reconnect the tubing and you're done. The main mistake you can make is to add too much, in which case you'll need to fish a piece of paper towel (or pipe cleaner) down into the fill hole to remove some excess. I made that mistake, but even so, the whole process was 10 minutes.

Arrived quickly and was just what we needed to replace fluid in a radon mitigation system when the guage was moved and spilled.