Testing 0.25 In Water Manometer

[paulmars]

I need to test this gauge. It reads -0.25 to 0 to +0.25 in water. Im using it in the 0.02 to 0.03 negative and

positive ranges. What of known value can I use to deflect this gauge maybe .1 or .05 in either or both

directions to test the gauges accuracy?

pa
 

[exchemist]

I need to test this gauge. It reads -0.25 to 0 to +0.25 in water. Im using it in the 0.02 to 0.03 negative and

 

positive ranges. What of known value can I use to deflect this gauge maybe .1 or .05 in either or both

 

directions to test the gauges accuracy?

 

pa

 

I'm afraid I can't understand this. What are you doing and what are the units in which these numbers are expressed?

[paulmars]

check the accuracy of the gauge.

 

inches of water,

[exchemist]

check the accuracy of the gauge.

 

inches of water,

If it is a simple U tube manometer with water in it I don't think any calibration or accuracy check is needed, as the pressure difference translates directly into a height difference of a substance of known density. More here: https://www.sensorsmag.com/components/manometer-basics

 

I suppose in theory the density of water changes slightly with temperature but I should not have thought this effect would be significant for the types of application for which a water manometer is generally used. 

[paulmars]

mount it inclined 10:1 for 10 times the resolution. https://www.amazon.com/Yellow-Jacket-78075-Water-
Manometer/dp/B0038QHTK2/ref=sr_1_5?ie=UTF8&qid=1520466840&sr=8-5&keywords=manometer

its graduated at 0.25 intervals and you can easily judge 1/5 of that. So, 0.25 included 10:1 the 0.25 would then be 0.025 and I could fairly accurately judge 1/5 of that or 0.005.

thoughts?