PTS Flowbench Forum

Posted: **Sat May 29, 2010 6:57 pm**

1960FL wrote:Strf,

I might of been a little unclear also do you read your scale in MM or Inches?

Rick

Rick,

Even though the entire world is now officially running on metric measurement, (apart from America) some things are still always traditionally measured in imperial units.
Test pressures are always still measured in inches of water everywhere.
No need to provide alternative metric test pressure units for non Americans.

Likewise vehicle wheel rim widths and diameters are always in inches all over the world.
For instance a 185/65/14 radial tire uses a fourteen INCH tire rim with a tire width of 185 mm.

We still order chicken wire from the hardware store in inch, or inch and a half mesh, but the rolls are 1200mm or 1800mm wide.
The standard pitches of industrial sprocket chain are still in fractions of an inch, but the chain is sold per meter.
It is a crazy world, but we metric people are very used to seeing things measured in inches all the time, and there is nothing at all unusual about that.

Posted: **Sat May 29, 2010 8:35 pm**

Tony,

Thanks for clarifying that, I have always struggled with grasping the metric system in a practical manor as I am a very visual person and a machinist and have never got my head around 6mm is like ¼” and 13mm I like ½” etc. I have been forced to work in it when doing projects using many bearing types and the bearing industry is a mixed bag of metric and imperial sizes even on the same bearing.

I was actually kinda fishing here as I feel the true answer in this whole specific gravity issue is to use that old 1000mm stick and build a nice spreadsheet like Stef has and forget it. You can put marks on your depression scale for the equivalent of 10”, 25”, and 28” and let the spreadsheet do the rest. I find it an incredibly easy system especially on the incline as you could use a 500mm rule and you will be incredibly accurate. Set the depression to 741MM (for dot 5) and read the incline scale, plug the spreadsheet and go. The fact that the computer is doing the SG compensation becomes a natural. I have struggled with this debate for a long time and do not understand why it is always overlooked, using metric rules take so much out of the guessing and you can enjoy the value of and equal 10 devisor scale. (Kind of like me and a machinist rule)

I feel like since the incline is a none linear equating value and to not create confusion between the different SG fluids big blue uses, they came up with the % scale, then you still had to do the math. Don’t get me wrong if you are one of those people that still do every thing long hand on paper and pencil this is not for you, but if you have the computer near by this is a simple easy way to work the monometers with any SG fluid you like.

Thoughts?

Rick

Posted: **Sat May 29, 2010 9:14 pm**

I made my sloping manometer scale 1,000 mm long, simply because it is a lot easier to mark that off in percentage flow increments. It is a lot easier to precisely locate (say) 440mm or 440.5mm on a one metre long steel ruler than pick off 17.324 inches from an inch scale.

If I wanted to build a fluid test pressure manometer to set test pressure in increments of inches of water, I would much prefer an inch graduated scale to set my pressure against, rather than some "corrected" metric scale.

I use both imperial and metric interchangeably, because as you say, bearing and shaft sizes can be a mixture of both. Just assembling a Dana 30 diff from a Nissan vehicle right now. The American gears, bolts and bearings of the diff center itself are all imperial, but the axle shafts splines end bearings and pinion drive flange are all Japanese metric. A real total mess.

I guess it depends what part of the world you live in, but in Australia we used to be imperial, but shifted to metric. And many things here are still imperial. My lathe uses imperial lead screws, and all the slides are marked in thousandths of an inch. To turn something metric is a real pain.

I suppose even in America you are seeing a lot of imported metric stuff, and there is no real way around the problem for any of us.

Posted: **Mon May 31, 2010 12:37 pm**

Tony,

I hear what you are saying but please help my Pea Brain understand in the day of the computer the advantage of the %scale other than some company did it so we should too. Maybe I am all wrong but if i have a 150CFM plate in my bench and my incline reads 63.5% my DA still needs a calculator to know I was flowing 95.25CFM

As you can see i just struggle with this from a scientific test perspective in my world once we start mixing scales what is the difference between 28" of water and 741MM of DOT 5? Especially when we are testing on our own bench for comparative analysis.

Just a thought,

Rick

Posted: **Mon May 31, 2010 5:23 pm**

1960FL wrote:Tony,

I hear what you are saying but please help my Pea Brain understand in the day of the computer the advantage of the %scale other than some company did it so we should too.

Not everyone has access to a differential pressure data acquisition system, or the computer and electronic skills to do it all themselves.
For some, a home made sloping water manometer may be closer to financial reality.

Ditto for a water test pressure manometer.
Not all of us live in frigid regions of ice and snow.
In a much more friendly climate, an ordinary water manometer works just fine.

Posted: **Mon May 31, 2010 10:14 pm**

Tony,

I agree with all your points I am just looking for the intermedium between % scale with calulator and PTS DM. Many who have raised the point about fluids have shown vast computer skills and I for one would like to see us move away from what Big Blue is doing and move toward some easy DIY Standard. MMO, DOT5, even Saflower oil. Maybe we should be looking for somthing good with a SG of .5

I could not agree more with water as it is universal and the standard but it is aproblem for some.

Rick

Posted: **Tue Oct 26, 2010 6:25 pm**

Update of sorts... I have been using flourocine (sp) with distilled water and a little soap for a good few months now with no problems like clogging or gunking up. I would recommend the flourocine over food dye and you don't need much of it to colour the water.

Posted: **Mon Nov 08, 2010 4:18 pm**

And if you use a UV lamp to illuminate the flourocine, it will glow very brightly indeed at very low concentrations.

Posted: **Sat Jan 01, 2011 2:19 pm**

1960FL wrote:Stef,

Your point is taken well but only if you are planning on doing everything in long hand arithmetic. I have searched High and Low for an economical fluid that could be used to replace water with the accuracy of water! There a lot of fluids with an SG of .99 to 1.01 but all you do not want to be around (Touch, smell etc). You could get into mixing multiple fluids like Dot 5 & something that is say 1.04 (Dot 3) in a 50/50 mixture to get an SG of 1.0 but then again your searching for something that will mix and still be clear and fluid and not gue in my brake line… The point behind Dot 5 was most of us use a computer to do the calculations and therefore it is easy to adjust for the SG difference. The SG has little to no effect on the incline as this is not a linear scale and unless you are using a % scale it is just a number you plug into a formula, then again if you are using a % scale you most likely made that so adjust it for the .963 SG. So for me if I know that my test depression is 28” then I set my mark at 29.0758  but remember if I am using water that could be from 28 to 28.125+ depending on where you got your water and how contaminated it is (Saponifier, dye, etc) ?

So my point is with our ability to do advanced calculations on the fly and since Depression is just an arbitrary point no one can decide on (10”, 16”, 25”, 28”, 34”, 40”,60” etc.) A known line on a stick is just fine, the rest is math as long as you consistently set your depression to that line on the stick, then again maybe we can get Bruce to have a vertical monometer scale made to a .963 SG fluid LOL!

IMHO and of course my working on the project gives me bias, I like Water as a Datum and find life a little simpler using the PTS Digital Monometer.

Thoughts?

Rick

After thought http://www.whittamprecision.co.uk/rfq.htm

figured it would be better to warm this thread back up then to start a new on.

My U tube will soon be eliminated with Bruce's motor control, Which is GRATE!!! NO MORE FROZEN GAUGE TO MELT!
BUT, my incline is colored water to!

My incline is is 12" rise, 36 long
I got a spread sheet from the old forum to convert the incline inches to cfm.

Here's the Question
can i just change the water to "Marvel Mystery Oil" and change the sg from 1.0 to .8xx of MMO
O Crap it don't figure it that way in my spread sheet.
It came off of the old forum. The first on is for calibrating my bench and the 2nt if for the incline......thought it just had a SG number that i could change.

It shows Density of Water at 62.28 lb/ft2(don't know how to make a small 2)
What is Density of MMO in lb/ft2

It's in Microsoft excel (non commercial use) but i have no clue how to take a pic of it and post it..........................

I will just take a picture LOL

Posted: **Sat Jan 01, 2011 3:39 pm**

Flash wrote: Here's the Question
can i just change the water to "Marvel Mystery Oil" and change the sg from 1.0 to .8xx of MMO
O Crap it don't figure it that way in my spread sheet.
It came off of the old forum. The first on is for calibrating my bench and the 2nt if for the incline......thought it just had a SG number that i could change.

It shows Density of Water at 62.28 lb/ft2(don't know how to make a small 2)
What is Density of MMO in lb/ft2

It's in Microsoft excel (non commercial use) but i have no clue how to take a pic of it and post it..........................
I will just take a picture LOL

If you need an old spreadsheet attachment from the old forum I can upload it here. Plan is to do this sometime with the one's that were pretty much "required" reading.

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