SMAN3 calibrated?

[redback]

FP Australia sent me a 2nd hand used sman3 to replace my cracked one, I have charged some capillary cabinets since recieving the 2nd hand sman3. I realised today that the pressures on the lo and hi side is 0PSI if the hoses are disconnected, but if I cap the lo an hi side and open both valve's and pressurize the centre port I get 62 PSI on the low side it is 78 PSI on the high side when they should be the same.

So I now fear I have charged many units incorrectly and will have to go back to each of them.

What Im trying to detirmine is if this is a faulty pressure transducer or the 2nd hand unit was not calibrated by Fieldpiece Australia before they sent it to me.

The other issue is the 2nd hand sman3 they gave me has the old style piston valves fitted, the one I sent away had new style piston valves.

[Pascone10]

Sounds like another issue with a Fieldpiece digital manifold...

When I would talk to Doug Lockhart from Digicool he would explain about the poor design of some transducers and other components ( not any manufacturer specifically) and explain it was only a matter of time until there were failures. He was spot on!

Sorry, you should have done some research here and picked up a digicool set. If you had you would not have to worry about doing your job twice..

Why did you get a second hand set from Fieldpiece?

[jnsrose]

Easy there buddy. I know you are a big digicool fan but some of us love our smans. I am a digicool fan as well but also an sman owner. There are some flaws but they are an execellent manifold.

[Pascone10]

Sorry about that:cheers:. I didn't think that was a bad response.

I find it funny when there are multiple posts a week about how the Testo's or Fieldpiece are failing. There are so many posts about digital analyzers lately. I can pretty much sum them up.

1. What one should I buy?
If someone replies digicool the response by many is they are too expensive ( that was before the ak900's).

2. The other majority of posts were the failures with..
Fieldpiece; Transducers, clamps breaking from poor plastic, High side valves failures

Testo; Temperature clamps not reading on unit, Clamp failures, Transducer faiures..

Digicools; someone stepped on or ripped the wires for the temp clamp. (User error)

WHat I love about the digicool is I can fix it myself if I ever had to. That is pretty cool if you ask me..

Jns, Do you own the 1250's or the 900's?
What do you use more often? Fp or DC? Just curios.


In any event everyone enjoy the Holiday! Thank a Veteran.

[mark beiser]

There are some flaws but they are an execellent manifold.

Well, if those "flaws" regularly affect the core function of the instrument, refrigerant pressure readings in this case, no amount of extra features can possibly make up for the "flaw".

[dunkman]

I'm not surprised at all. One of my coworkers bought a SMAN3 a couple months ago. He was showing it off to me for the first time last week while I was showing him how to do a heat pump startup. Upon running the cooling we had a suction pressure of around 78 psi, superheat 30 deg. Subcooling of 8 deg, R410a. Hmm, loooks like a bad txv. I never gave it a second thought since I've been trusting my digicool 1250 for a year and a half now. After we found another TXV and swapped it out, same exact pressures.......... Crap. I marched to my van grabbed the 1250, tied it to his SMAN. Hmm that's weird, yours says 78psi, mine says 115psi. We were running a nice 12 or so superheat the whole time. Funny thing was his loside shows 0 at atmosphere, but it's 30 psi off at the mid range. Needless to say, I'm happy I spent the extra couple hundred bucks, at least mine does what it's supposed to do.......... Arrrrggghhh!!!

Just another true testimony.

[mark beiser]

Just another true testimony.

One of the reasons I use the overly complicated hose sets I use is so that I can always verify that both sides of my gauges read the same when exposed to the same pressure when I first connect to a system, then again when I disconnect from the system.

Every once in a while I haul every thing out into my living room and daisy chain all my manifolds together connected to a jug of refrigerant to make sure everything is calibrated properly.

I did that tonight with my main R-22 set, DRSA-1250, and my main R-410a set, Testo 550, along with my Fluke 52II with 2 fluke pipe clamps, a couple of Testo H2's, and a Fieldpiece PRH3.
Gives me a warm fuzzy feeling that the pressures were all within 0.5 psi, correct PT relationship, temps all within 1º, and digital psychrometers all within 0.2ºwb. :D

This weekend I'll probably haul out my old Digi-Cool BTD-1000 and first gen Testo 523, and more temperature instruments and probes.

I've never sent anything in for an official calibration, but I've got plenty of instruments and probes, using enough different technologies, on hand to compare against.
If 3-6 instruments/probes are telling me one thing, and 1 is telling me something different, I'm pretty confident the 1 is wrong. ;)