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Thread: Job link manometers

  1. #1
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    Job link manometers

    Since Iíve been bitten by the wireless bug and really really liking the wireless charge kit. Today I picked up the wireless manometer kit just because I wanted it. Do many of you guys have those and how have you liked them so far? Any issues to be aware of or tips and tricks I should know? So what say you

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    They work fine. I don't use them on every call, just where I suspect airflow problems. MQ can use SP readings, but I think I remember Jim saying that the formula they use to determine airflow is more accurate.

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  4. #3
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    Iím thinking about getting this set also. Not only for static pressure but for checking gas pressures on furnace.


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    Quote Originally Posted by 270wsm View Post
    Iím thinking about getting this set also. Not only for static pressure but for checking gas pressures on furnace.


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    Iíve had the regular fp manometer for a little while and really like the idea of being able to check a run of duct from like one end to another or something to that effect and the wireless will allow me to do that without having to have 50ft if hoses wich I canít help but think would skew the measurements. Iím excited to find a good reason to break em out and play with.

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    Quote Originally Posted by vin lashon View Post
    They work fine. I don't use them on every call, just where I suspect airflow problems. MQ can use SP readings, but I think I remember Jim saying that the formula they use to determine airflow is more accurate.
    Think I remember something like that as well. I donít use my manometer on every call either. Same as you just when I suspect a problem or am trying to figure out whatís wrong with certain things. I like to make a before and after measurement when I clean a nasty blower section so that I can prove to the people that it really did need it and I wasnít just trying to get money out of em for nothin.

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    Can one take static reading with a probe up into the supply grill and maybe the other probe where that duct run starts, like for example stick a probe up in the grille and the other at maybe the wye and see if the flex or whatever is bunched up and the wye or something in that nature? If that makes any sense.

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    Quote Originally Posted by Hurst11 View Post
    Can one take static reading with a probe up into the supply grill and maybe the other probe where that duct run starts, like for example stick a probe up in the grille and the other at maybe the wye and see if the flex or whatever is bunched up and the wye or something in that nature? If that makes any sense.
    I've never tried it, but I'd think you could, just like checking across a filter. Presumably, the SP reading would be higher on the plenum side of there was a kink in the duct. Also, depending on the length of the duct, you can anticipate losing some velocity any way due to friction.

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    Quote Originally Posted by vin lashon View Post
    I've never tried it, but I'd think you could, just like checking across a filter. Presumably, the SP reading would be higher on the plenum side of there was a kink in the duct. Also, depending on the length of the duct, you can anticipate losing some velocity any way due to friction.
    Thatís my thinking as well. I have stumbled across places where people have spliced a run without a piece of hard pipe and just stuck the inner inside the other and the way they slid the outer over the other without any tape itís not visible really at all unless you knew it was there or like i did just happened to find it when trying to figure out the reason a customer is complaining of poor airflo in their bedroom. Itís amazing the stuff we run across thatís prolly been like that for several years. Just seems to be a good thing to add to the arsenal that would be very difficult with a normal manometer.

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  12. #9
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    Ran into this a month or so ago. Customer was complaining that bedroom was getting no air. The duct looked fine, but pressing on the insulation was soft. This one foot gap was under the insulation. Note the handy use of romex for support. I spliced in new pipe, wrapped and masticed and used proper duct strap to fix. Real purty when I finished. I forgot to get the after shot. I run into a lot of shoddy work in this region. Most duct systems and R/A intakes are undersized.

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  14. #10
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    I have them and they are great for testing static pressure but for gas pressure I use the regular Fieldpiece dual port manometer.

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    I have them and use them frequently. My only gripe is the drift. They’re easy to reset though. They do seem to drift together, so the differential stays pretty constant like the SDMN5.
    "The only true wisdom is in knowing you know nothing" Socrates

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    Quote Originally Posted by R600a View Post
    I have them and they are great for testing static pressure but for gas pressure I use the regular Fieldpiece dual port manometer.

    Sent from the Okie state usin Tapatalk
    Based on the published specifications, itís just as accurate as my Testo 510. I have used the Testo for years for setting gas pressure.


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    Quote Originally Posted by mgenius33 View Post
    I have them and use them frequently. My only gripe is the drift. They’re easy to reset though. They do seem to drift together, so the differential stays pretty constant like the SDMN5.
    Could you educate me on the drift your talking about?

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    Quote Originally Posted by 270wsm View Post
    Based on the published specifications, itís just as accurate as my Testo 510. I have used the Testo for years for setting gas pressure.


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    The reason I use the regular dual Port manometer for gas pressure is just convenience. I don't need to be juggling a phone along with everything else when I'm checking gas pressure. I prefer a manometer that has its own screen for that.

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  20. #15
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    Quote Originally Posted by Hurst11 View Post
    Could you educate me on the drift your talking about?
    Most all electronic pressure sensors will drift from zero while in operation causing the displayed measurement to also drift from actual. This drift adds to the inaccuracies and I highly doubt drift is calculated in the “accuracy” of the tool. Some high end manometers use an auto-zero function which uses a solenoid to remove the sensor from the circuit to zero at set intervals usually 10 seconds or so. Maybe it has a greater affect if the tool hasn’t warmed up. It seems to me the drift reduces the longer the tool is in operation.

    The only dual port manometer I’ve found to have little drift is the iManifold 921m. This may be because it uses only one sensor that reads from both sides, IDK.
    "The only true wisdom is in knowing you know nothing" Socrates

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    Fluke micro-manometer is also very low drift.


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    Quote Originally Posted by mgenius33 View Post
    Most all electronic pressure sensors will drift from zero while in operation causing the displayed measurement to also drift from actual. This drift adds to the inaccuracies and I highly doubt drift is calculated in the “accuracy” of the tool. Some high end manometers use an auto-zero function which uses a solenoid to remove the sensor from the circuit to zero at set intervals usually 10 seconds or so. Maybe it has a greater affect if the tool hasn’t warmed up. It seems to me the drift reduces the longer the tool is in operation.

    The only dual port manometer I’ve found to have little drift is the iManifold 921m. This may be because it uses only one sensor that reads from both sides, IDK.
    If Iím understanding this correctly then if after the device was zeroed but didnít actually use it to check something and just left it hooked up and working but at idle, that it would ďdriftĒ off of that zero?? If so wich direction does the drift go, higher than the zero or lower. What I mean is say if I hooked up to check manifold gas pressure but didnít turn the furnace on, would it at some point show a reading other than the zero, or is the drift happening only when itís actually measuring something?

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  24. #18
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    Quote Originally Posted by Hurst11 View Post
    If Iím understanding this correctly then if after the device was zeroed but didnít actually use it to check something and just left it hooked up and working but at idle, that it would ďdriftĒ off of that zero?? If so wich direction does the drift go, higher than the zero or lower. What I mean is say if I hooked up to check manifold gas pressure but didnít turn the furnace on, would it at some point show a reading other than the zero, or is the drift happening only when itís actually measuring something?
    Yep just sitting there it'll drift. Fieldpiece says to take your measurement within 2 minutes of zeroing it. My theory is that temperature change is the biggest factor causing drift because it seems if the meter is already up to the room temperature where I am testing it doesn't drift much but if I bring it in from an ice cold truck into a warm house it'll drift like crazy.

    Sent from the Okie state usin Tapatalk

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    Quote Originally Posted by R600a View Post
    Yep just sitting there it'll drift. Fieldpiece says to take your measurement within 2 minutes of zeroing it. My theory is that temperature change is the biggest factor causing drift because it seems if the meter is already up to the room temperature where I am testing it doesn't drift much but if I bring it in from an ice cold truck into a warm house it'll drift like crazy.

    Sent from the Okie state usin Tapatalk
    Iíll be damn, never heard of the drift but will keep a look out for it.

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  27. #20
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    Quote Originally Posted by vin lashon View Post
    MQ can use SP readings, but I think I remember Jim saying that the formula they use to determine airflow is more accurate.
    As far as I am aware, MQ makes no "calculations" based on TESP. MQ makes airflow calculations based on the change in return air to supply air and the system tonnage profiled. JB did say that MQ is more accurate than TESP at air flow estimation in a resi application, but he also said that your super heat needs to be correct in order for MQ to estimate the air flow accurately. If you are running 35 degrees of super heat, because of a low charge or restriction, MQ will greatly over estimate your air flow because it is making the estimate based on the tonnage that you profile the system at and the change from return to supply. You can see this for yourself by observing how the air flow estimate goes down as you add charge and super heat goes down.

    I think that as long as the evap is not starved or flooded, MQ is better than TESP for air flow estimates in resi application. MQ won't be mislead off by dirty blower wheels, non OEM motors or system effect. It is sometimes difficult to find a spot close to equipment with laminar air flow to take static pressures.


    I have been comparing TESP/blower chart CFM estimates to MQ estimates on new system commissionings for some time. I have found the 2 methods to typically be within 30-50 "total system" cfm of each other.
    -Marty

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