On 07/22/2013 14:55, Jan Sennesael wrote: > I have several DS18x20 sensors in my network, some DS18S20 (the first 12) > and some DS18B20 (some more added later). > > Since i was unsure about some reading of some DS18S20 sensors i used a > second DS18B20 on the same spot... > That reading was about 2°C higher than the DS18S20... i moved it about and > it always was showing +-2°C higher dan the DS18S20 sensor it was next. > All these sensors are parasite powered. > After this i retried it with another DS18S20 (connected to the +5V - no > parasite power) and this one was 2.5°C higher dan the DS18B20... > > The DS18B20 are sampled directly from maxim, thus should be genuine. The > DS18S20: some are samples from Maxim, and others i bought of ebay. > > Does anyone know why there is is such a difference? (and mabe a solution?)
These sensors are supposed to report +- 0.5C (factory trim). Try an ice bath as suggested to see what the differences are between sensors. They should be not > 1.0C between devices and typically much less. /m ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
