Questions for traversing with a pitot tube

[WAYNE3298]

The dry coolers typically cool small loads in plants where they want to operate equipment on a part time basis.
You are good with the inclines you have. Yes they do need to be level but the trick some people miss is it is best to leave them in the space you are going to use them in long enough for the liquid temperature to stabilize. If not get the pitot run as quickly as possible and keep an eye on the zero. Oil or water doesn't expand much but it doesn't take much on that instrument. I got burned on that once and luckily noticed it after the traverse was done and redid it. If the inclined is calibrated it really is as good as lab calibration but you can't certify anything calibrated with it as NIST traceable.
My inclines are the go to guys in case of problems and since retired they are used to calibrate some of my equipment. Saves a lot of money and time.

[queequeg152]

The dry coolers typically cool small loads in plants where they want to operate equipment on a part time basis.
You are good with the inclines you have. Yes they do need to be level but the trick some people miss is it is best to leave them in the space you are going to use them in long enough for the liquid temperature to stabilize. If not get the pitot run as quickly as possible and keep an eye on the zero. Oil or water doesn't expand much but it doesn't take much on that instrument. I got burned on that once and luckily noticed it after the traverse was done and redid it. If the inclined is calibrated it really is as good as lab calibration but you can't certify anything calibrated with it as NIST traceable.
My inclines are the go to guys in case of problems and since retired they are used to calibrate some of my equipment. Saves a lot of money and time.

excellent point regarding the oil. i assumed the expansion would be negligible in what ever oil they formulated, but i guess not. im going to have to stalk your older posts man, you give out tons of good information.

on an unrelated note, i love my acrylic manometers, so pretty an elegant. i have like... 5 now? including a dwyer microtector model 1430 that i have yet to tinker with(fluid spilled during shipping). its too bad they are discontinuing so many of them.

[WAYNE3298]

I use red oil in my incline and it's not fun when you spill it. Most folks like digital now days and that's OK but nothing beats the accuracy of water. You are correct the expansion of water in the incline is not much of a problem and none at all in the standard vertical manometer.

[queequeg152]

the microtector uses a water based fluid with some flourescent dye, and a surfactant to eliminate some of the meniscus. i think some of the vertical manometers still use the same fluid luckily.

the thing uses the depth micrometer as an electrode basically, so the fluid needs to be conductive to some extent.

its still available on their site somewhere, i just have not had a chance to look it up.

[tridiumtech]

Going back to the Thread subject (traversing), after performing the method WAYNE3298 suggested (6" spacings, 3" from sides), for kicks try the quick "4-point" method (from Gil Avery, Kele Assoc.). I'm curious how close it came to the 16-point method.

I saw a 2-guy team perform an 80-point traverse on an AHU cooling coil - took 1hr. The "4-point" method would of only have taken minutes. Accuracy was spot on.

For official NEEB-type of balancing, the full-point method is mandatory, but nice to know this option.

See attached PDF.

[WAYNE3298]

tridium,
The method I gave was the equal area method. On one job the engineer wanted the Log Tchebycheff method used which instead of 16 readings on a 24 inch duct requires 36 readings.