PTS Flowbench Forum

It seams to be about 0.7-ish bounce, maybe even more at certain lifts - think I saw a 1.1 -.

I'll see if I can download it and slow it down in Potplayer.

That video is a weird one.

It has auto dep control, but the dep creeps. The cfm auto converts to 28" and when it first hits 28" the cfm is pretty steady and around 0.2 fluctuation, but as the dep creeps higher the numbers move and change, like the whole system has lag and it's catching up, and it's hard to tell if it's fluctuation on lag. At 0.700" it move 1.1, and at the end of the video the numbers are still rising, so I can't tell what a steady reading is.

You can download the video on this site

http://catchvideo.net/

Download the English version of Potplayer - I think this is it -.

http://www.majorgeeks.com/files/details/potplayer.html

press x a couple of times while it plays until it's slow enough to see the numbers change.

I have a Performance Trends Black box and it interprets the bounce as turbulence. I have found this to be mostly true. The smoother I get the port to sound the less the bounce is.

John

Grey,

Here's something you'll find interesting

Old Grey wrote:That video is a weird one.

It has auto dep control, but the dep creeps. The cfm auto converts to 28" and when it first hits 28" the cfm is pretty steady and around 0.2 fluctuation, but as the dep creeps higher the numbers move and change, like the whole system has lag and it's catching up, and it's hard to tell if it's fluctuation on lag. At 0.700" it move 1.1, and at the end of the video the numbers are still rising, so I can't tell what a steady reading is.

You can download the video on this site

http://catchvideo.net/

Download the English version of Potplayer - I think this is it -.

http://www.majorgeeks.com/files/details/potplayer.html

press x a couple of times while it plays until it's slow enough to see the numbers change.

I saw that with the depression too... Pathetic flow test IMO. No stability, no accuracy....

Yes it's weird.

I'm assuming that it's does internal conversion to 28" - think I saw it in the SF1020 -, so even if the dep creeps up why are numbers changing after the fact - it's like it's lagging behind -.

jfholm wrote:I have a Performance Trends Black box and it interprets the bounce as turbulence. I have found this to be mostly true. The smoother I get the port to sound the less the bounce is.

John

The Black Box has some good features, I think it gives the % bounce so you can actually gauge the port by a turbulence number.

larrycavan wrote:

slaa034.pdf

Grey,

Here's something you'll find interesting

Larry, you're killing me
Even though I'm not an elec eng I still get the gist of it. I wanted to get more into analogue/digital interface stuff, but I'm just lacking the motivation currently.

The thing about this digital stuff is that there is a dozen ways to skin this cat, and all seam to work when you get used to the foibles - the PTS DM probably has the least, if any -

Old Grey wrote:Yes it's weird.

I'm assuming that it's does internal conversion to 28" - think I saw it in the SF1020 -, so even if the dep creeps up why are numbers changing after the fact - it's like it's lagging behind -.

jfholm wrote:I have a Performance Trends Black box and it interprets the bounce as turbulence. I have found this to be mostly true. The smoother I get the port to sound the less the bounce is.

John

The Black Box has some good features, I think it gives the % bounce so you can actually gauge the port by a turbulence number.

larrycavan wrote:

slaa034.pdf

Grey,

Here's something you'll find interesting

Larry, you're killing me
Even though I'm not an elec eng I still get the gist of it. I wanted to get more into analogue/digital interface stuff, but I'm just lacking the motivation currently.

The thing about this digital stuff is that there is a dozen ways to skin this cat, and all seam to work when you get used to the foibles - the PTS DM probably has the least, if any -

That point of the document was to show you the reasons that band aids get applied to digital devices. Ultimately costs drive the approach and solutions. And YES there is more than one way to approach this.....

But something that I think people fail to understand is that with orifice benches, the environment in which the orifice lives determines the readings you will get from any device, mechanical or digital and also influences the stability of the readings. It's air being influenced to move through a hole by some means. What happens to it along the way can and will cause some variances that you ultimately experience....

Here are my ludicrously over designed control valves - stop laughing -

When you have 45º joints in wood it easy to put a bend in the board - neither board has much second moment of inertia -, and coupled to the poor construction of the original builder the base plates have to be shimmed to square them up to the screw






When the sealer dries I will test them out.

If anyone wants drawings, just tell me - it saves you working out dimensions -

Wow that looks like a bit of work, I hope you find what your looking for Grey. I think you just won the "top engineered" award today. I think I'll just stick with controlling the motor speed electrically. That bench is looking as good inside as it does outside. Nice work

Nice job...I love it