XPost: at.home.repair, uk.d-i-y   
   From: CFKinsey@military.org.jp   
      
   On Sat, 11 May 2019 22:38:42 +0100, alan_m  wrote:   
      
   > On 11/05/2019 19:54, Commander Kinsey wrote:   
   >   
   >> I know the multimeter is accurate, I've tested it on all sorts of things.   
   >   
   > The only way you will know that your multimeter is accurate is by having   
   > it calibrated against a known standard, ideally specified to 10x better   
   > than your meter.   
      
   Or by using it to measure a known current on a bulb I know draws a certain   
   current.   
      
   > At 0.65A a high end Fluke multimeter @ £200+ will give 0.65A +/- 0.01A   
   > on a typical £50 multimeter £50 it will give 0.65A +/-0.09A   
   >   
   > Without a specification for what you have purchased, you may have meter   
   > capable of measuring fairly accurately currents in the range 100A to   
   > 1000A but not capable of 0 to 10A measurements with any degree of accuracy   
   >   
   > Typically you may be trying to measure and compare a 0.65A current with   
   > measuring equipment with a total uncertainty of measurement of around 0.6A   
   >   
   >  > The 8.5A was measured both with one of those energy efficiency meters   
   >  > on my house's meter tail, and by knowing what devices were running.   
   >   
   > So your comparison standard is something British Gas used to give away   
   > for free, possible so inaccurate that it hasn't got a published   
   > specification for its current measuring capability.   
      
   "and by knowing what devices were running"   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)