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  • Gauge accuracy

    When we took possession of the Linea I set it up at 9 bar with a pressure gauge...an expensive one - not one that was cobbled together. Once the adjustment was made, the gauge on the Linea also read 9 bar, yet I remained suspicious that the pressure was a little low.

    Earlier this week our Scace 2 arriived (they should rename these as "Scarce 2"). It told a different story with a reading of 105psi or close enough to 7.3 bar.

    The temperature reading differed to the PID by a couple of degrees, though that was to be expected.

    For me, the moral of the story is that gauges fitted on espresso machines are more useful to simply determine if whatever they are measuring is working or not. But whatever you do, dont rely on them for accuracy. Im thinking the same can be said for pressure gauges.


  • #2
    Re: Gauge accuracy

    Unfortunately, so true, often a guage is only an indication. The other interesting point is that someone who is conscientiously operating the machine will usually have a reliable sense of whether it is operating in suitable ranges, irrespective of what gauges indicate.

    Some time ago, I tested my Silvia using the pump flow rate method and it indicated that brew pressure was OK, however I still thought it was a bit high...subsequent testing with two different gauges showed it was, typically, a bit high and has since been adjusted. I am happier with the performance, but can only assume that the brew pressure is around 9bar...

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    • #3
      Re: Gauge accuracy

      Back in my work history when I had a real job we used to sell NATA calibrated pressure gauges. Even some of the non certified ones we sold were a lot better than the average industrial ones.

      I suspect that with ones on coffee machines over time they suffer from the same scale build up issues in the fine capillary tubes internally causing them to become inaccurate and even develop a hysteresis problem.

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      • #4
        Re: Gauge accuracy

        When we took possession of the Linea I set it up at 9 bar with a pressure gauge...an expensive one - not one that was cobbled together.  

        Did this expensive guage allow water to pass through it like the Scace2 (to simulate actual extraction conditions) or was it like a blind filter?

        Once the adjustment was made, the gauge on the Linea also read 9 bar, yet I remained suspicious that the pressure was a little low.

        Earlier this week our Scace 2 arriived (they should rename these as "Scarce 2").  It told a different story with a reading of 105psi or close enough to 7.3 bar.


        Interesting that two guages should be out by the same amount, and the Scace assumed accurate. Did you check the Scace against any other reference?

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        • #5
          Re: Gauge accuracy

          Originally posted by 6A7C7979686A666F6F6C6C090 link=1292410251/0#0 date=1292410251
          Earlier this week our Scace 2 arriived (they should rename these as "Scarce 2").
          Too right. I have been trying to buy one for at least 6 months.

          The one mob that sell them are all over Twitter and elsewhere. When I asked how come they can be so prolific there and yet have not had time to respond to a single email I sent requesting an update, I copped an earful... :

          It would seem that Scace is not interested in producing them.

          How good would it be if a handy CSer could make a tool to do the same job which could be purchased in Oz? I chould then tell em to go pressure test their kyber pass  ;D

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          • #6
            Re: Gauge accuracy

            Originally posted by 1E3F363835235A0 link=1292410251/3#3 date=1293439695
            or was it like a blind filter?
            Like a blind.

            Originally posted by 1E3F363835235A0 link=1292410251/3#3 date=1293439695
            Interesting that two guages should be out by the same amount
            Youve misunderstood - there is only one gauge on the linea that measures pressure.

            Originally posted by 1E3F363835235A0 link=1292410251/3#3 date=1293439695
            Did you check the Scace against any other reference?
            Yes - on a mates machine that had been recently scaced with another scace. (Does that make sense?)

            Originally posted by 1E3F363835235A0 link=1292410251/3#3 date=1293439695
            and the Scace assumed accurate
            Nah, Ive been around long enough not to fall for that.

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            • #7
              Re: Gauge accuracy

              How good would it be if a handy CSer could make a tool to do the same job which could be purchased in Oz? I chould then tell em to go pressure test their kyber pass  Grin

              Im working on that at the moment, should have a prototype by the end of next week  

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              • #8
                Re: Gauge accuracy

                Youve misunderstood - there is only one gauge on the linea that measures pressure.

                No misunderstanding, to your original quote "I set it up at 9 bar with a pressure gauge...an expensive one - not one that was cobbled together. Once the adjustment was made, the gauge on the Linea also read 9 bar"

                Thats two guages, the one on the linea, and the calibration guage. Apologies for any confusion.

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