Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

In message , "Dr. David Kirkby (Kirkby Microwave Ltd)" writes: >I can't find it now, but I know someone said thermocouples are obsolete. I >spoke to a friend tonight who services industrial boilders. He said

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

On 5 June 2017 at 00:59, Attila Kinali wrote: > Moin, > > This discussion is kind of getting heated. > Let's put some facts in, to steer it away from > opinion based discussion. > I can't find it now, but I know someone said thermocouples are obsolete. I spoke to a friend

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Additional info/papers on Thermistor stability: http://www.digikey.com/en/pdf/u/us-sensor/us-sensor-stability-long-term-aging https://www.thermistor.com/sites/default/files/specsheets/T150-Series-Stability.pdf https://www.vishay.com/docs/49498/ntcs-e3-smt_vmn-pt0283.pdf >From LIGO:

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Here's a NIST paper on Thermistor stability: http://nvlpubs.nist.gov/nistpubs/jres/83/jresv83n3p247_A1b.pdf Bruce > > On 06 June 2017 at 01:45 Bob kb8tq wrote: > > Hi > > Well, as part of the process of designing them into OCXO’s you do indeed > check their long

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

In message <20170605133013.526e8505158e68b6a8091...@kinali.ch>, Attila Kinali w rites: >> Where do digital sensors (e.g. ds1820 and some more recent parts from TI) >> fit into this ? > >AFAIK, these are all band-gap temperature sensors. The Ds1820 is based on the frequency difference

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi Well, as part of the process of designing them into OCXO’s you do indeed check their long term stability. The test is done in an indirect fashion so you only come up with a “it’s below the limit” sort of number. The typical process involves running a group of OCXO’s on turn to check the

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi, guys I have been following time nuts and volt nuts for some time out of interest and fascination. Although my personal backyard hobby is more along a volt nuts line, the two worlds often collide - like in this discussion of temperature sensors, and in particular their long term stability.

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi > On Jun 5, 2017, at 7:30 AM, Attila Kinali wrote: > > On Mon, 5 Jun 2017 01:18:59 +0100 > Adrian Godwin wrote: > >> Where do digital sensors (e.g. ds1820 and some more recent parts from TI) >> fit into this ? > > AFAIK, these are all band-gap

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

On Mon, 5 Jun 2017 01:18:59 +0100 Adrian Godwin wrote: > Where do digital sensors (e.g. ds1820 and some more recent parts from TI) > fit into this ? AFAIK, these are all band-gap temperature sensors. But unlike a discrete sensor, you have the problem that they only contain

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi If your objective is a resolution of < 0.001 C at something < 1 second, the current crop of digital sensors don’t quite do what you need to do. They are a terrific way to do wide range measurements that might feed into some sort of correction algorithm. A conventional thermistor bridge

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Where do digital sensors (e.g. ds1820 and some more recent parts from TI) fit into this ? On Mon, Jun 5, 2017 at 12:59 AM, Attila Kinali wrote: > Moin, > > This discussion is kind of getting heated. > Let's put some facts in, to steer it away from > opinion based discussion.

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

The other issue that needs to be considered is the drift in temperature sensor characteristics when operated at a constant temperature (as is typical in a continuously operated crystal oven). High quality thermistors can achieve drifts of around 1mK/month. Its unlikely that something as complex