The UT804 bench multimeter
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From: Joel Koltner on 3 Feb 2010 17:42 Hey Dave, In your review of the U1253A, when you took it outside, it wasn't clear to me... was there no visible display because the sunlight completely washes it out? Or because the batteries had become completely discharged? Any idea what the "B" models are going to have different? Thanks, ---Joel
From: David L. Jones on 3 Feb 2010 18:33 Joel Koltner wrote: > Hey Dave, > > In your review of the U1253A, when you took it outside, it wasn't > clear to me... was there no visible display because the sunlight > completely washes it out? Or because the batteries had become > completely discharged? The display completely washes out. Not surprising for OLED I guess, and to be fair Agilent admit in their advertising this model is for indoor use. That's why they still offer the LCD version too. > Any idea what the "B" models are going to have different? Agilent tell me it's just the case colour and some firmware upgrades, whatever that entails. Dave. -- --------------------------------------------- Check out my Electronics Engineering Video Blog & Podcast: http://www.eevblog.com
From: Mike Warren on 3 Feb 2010 21:55 Tim Watts wrote: >Mike Warren <miwa-not-this-bit(a)or-this-csas.net.au> > wibbled on Wednesday 03 February 2010 13:52 > >>The back panel is metal but not grounded except though the USB cable. > >That is clearly a fundamentally unsafe design - sounds to me that it should >be defined like UK "Class I" - [extraneous conductive parts] and thus >suitably grounded... Presumably there is a similar distinction of metal >cased[1] vs double insulated stuff in Oz? > >[1] But without secondary insulation internally, to be pedantic... The mains side of the power supply section is double insulated. The problem comes about if the test leads are connected to a dangerous voltage, since even if the switch had been soldered correctly, the gap from the terminal to the body is dangerously small, IMO. -- - Mike
From: Mike Warren on 4 Feb 2010 20:17
Tim Watts wrote: >Can't help feeling that they perhaps should have fully isolated the >measurement circuits from the computer interface (optically or >magnetically), but then people always moan I overegg everything ;-> Everything is isolated. The only possible place for a failure was on the AC/DC switch, which by necessity is electrically connected to the test probe side of the meter. They should had used a switch designed for isolation, or perhaps a plastic lever so the case would not be connected to the outside world. -- - Mike |