Red line v plane glass for boiler water gauges

[GreensandsParticipant @greensands]

I am considering replacing the 5mm plane glass sight gauges supplied with my boiler water gauges with the alternative red line glass. It would be however to se some close-up photos of just how effective the rd glasses are in practice. Can anyone oblige with some suitable pics?

[Nigel Graham 2Participant @nigelgraham2]

I’ve no photos I’m afraid, but as a rough guide a line directly on the tube is magnified to about twice width by the water.

The line can also be on a plate behind a plain glass tube, with slightly lower magnification. This perhaps more common on gauge-frames that enclose the tube in a protector, but the plate can be clipped to the fittings if not.*

An alternative, for the latter method, is alternating black-and-white, diagonal stripes.

I’d suggest before deciding to change anything, experimenting with marked cards behind the glass, with the water at about mid-glass.

 

=====

* As I did.

I have fitted my steam-wagon’s gauge-glass protector with a white-painted back-plate with three red-filled, narrow, vertical grooves; having tested if this would work by sighting it through a spare glass partly filled with water.

 

[Speedy Builder5Participant @speedybuilder5]

I use a bit of this behind the gauge glass on a 1/4″ od glass.

[Harry WilkesParticipant @harrywilkes58467]

Lined glass for me any day

H

[Author]

Posts