Initial Calibration help needed

[MCUBED]

Hey all:

We just got our bench (PTS plans and kit) up and running.

Ran the program for calibration and had two problems (and also one question).

Problem One: with the bench OFF but the computer "ON", it's reading 20 cfm, just sitting in the shop.

Problem Two: with the bench ON, we were getting 3 times (roughly) the CFM of the calibration plate being used (!) (Sorry, I wasn't operator so not sure WHICH plate it was...). Bench was set up for "intake"-- switches, directional plate, and calibration plate were double checked in the "correct" installation.

This then brought up Question: Shouldn't there be a screen where "conditions" are entered? (Temperature, humidity, barometric pressure, etc.?).

What are we missing in this initial calibration? We are ready to start testing!

Thx for all feedback!

M

[Brucepts]

Did you look in the PTS Flowsoft area for the installation manual it addresses the zero set number?

Did you change the plate size in Flowsoft configuration to match the plate you have inside the flowbench?

There is no need to change temps or baro in Flowsoft Configuration

[MCUBED]

Bruce:

Thx for quick reply! Alas, I'm just the "tester" NOT the computer user (yet), so my answers will be lame:

a) dunno
b) I thought so (?)
c) Thanks!

Will verify on Wednesday and post again with any improvements!

Much obliged.

M

[Bstinger]

Bruce thanks for your response, I am the 'operator' in question.

We had the manual but the figure was so far off I could not imagine that 'tweaking' the calibration figure would make a suitable adjustment, ie My guess is that the calibration would be way off at either extreme!
Am I incorrect in this assumption?
If so I will attempt the calibration per the manual ,at the next opportunity
The software was configured for the plate installed and we were calibrating against the next smallest plate
I assumed that atmospheric pressure changes (altitude being fixed), and temperature would effect the results!
I expected the software to be at 0 with no airflow, as this seems like a logical datum! And if the flow was 200 CFM out, why was it not 200 CFM out at no air flow, is the a bell curve effect at work here?
Am I wrong in my assumptions?

Simon

[1960FL]

Hey all:

We just got our bench (PTS plans and kit) up and running.

Ran the program for calibration and had two problems (and also one question).

Problem One: with the bench OFF but the computer "ON", it's reading 20 cfm, just sitting in the shop.

Problem Two: with the bench ON, we were getting 3 times (roughly) the CFM of the calibration plate being used (!) (Sorry, I wasn't operator so not sure WHICH plate it was...). Bench was set up for "intake"-- switches, directional plate, and calibration plate were double checked in the "correct" installation.

This then brought up Question: Shouldn't there be a screen where "conditions" are entered? (Temperature, humidity, barometric pressure, etc.?).

What are we missing in this initial calibration? We are ready to start testing!

Thx for all feedback!

M

Before you worry about the 20 CFm at rest please tell me what plate is inside your bench "the exact information on the PTS Sticker"

and the same as above for the calibration plate you are testing with on top of the bench.


Thanks Rick.

PS. did you check for leaks?

[Darcy R]

Also be sure to close, and re-open flowsoft after changing the plate calibration data. On my set-up, it does not take the changes until flowsoft is re-opened.

Darcy

[MCUBED]

Thanks for those tips!

We are trying again on Wednesday evening-- I'll update our results then.

Re: Leaks. We *did* find some between box and top plate, but corrected that. We seemed good, otherwise.

M

[Bstinger]

The plate in our box is for 300 CFM, diameter 2.045.

We have tried each of our other 2 plates on the top, one for 200 CFM (1.669) and one for 100 CFM (1.18) with similar strange results.

Any ideas as to why the CFM reading doesn't go to zero when all fans are off? It is zero when we start the software before starting the fans.

Simon

[Brucepts]

Did you read the part in the instructions that talks about "channel offset"?

Did you apply those instructions to your calibration?

A number showing at rest will not be effecting the end number, it's has to do with how the calibration numbers work and the fact you have no airflow. Once you have numbers in the averaging buffer those numbers stay there until you have new numbers show up, if you have no airflow no new numbers enter the buffer, once you turn the airflow back on the numbers will start moving again.

[Brucepts]

One other thing; the DM should be mounted flat with the label facing up. Mounting on it's side will effect the sensors and will show non-zero numbers until it starts moving air