thermocouple meter review - Page 1
Forum section: electronics / general

author: daniel444
author_rank: Regular Contributor
timestamp: April 02, 2021, 07:50:41 am
content: this holds two separate k type thermocouplesthe contacts that hold one of the thermocouples have lost all tensionattempts to bend them back have failedonly one set of contacts are affected , it still holds a single thermocouple properlyits almost as if the second set of contacts are of a softer metal???i suppose i could solder the thermocuople wires directly to the board but they are polarized , and im not sure its worth the timethe 18650 mod has allowed it to go 2 months instead of 1 week with aaa battery'sany one know of any good similar products ?

author: beanflying
author_rank: Super Contributor
timestamp: April 02, 2021, 08:29:12 am
content: Several things spring to mindK type thermocouples do not have very good accuracy typically at least +-1C and up to +-2C what they are great at is their operating range extremes. There is a reason the plugs are polarised the terminals are not made from the same metal and neither is the wire (NOT copper) as you are relying on the junction to provide a minute current any additional couples are avoided. So if you need new points then buy the right bits.So what to do for what looks like an ambient logging duty is go to the food industry and the little Elitech is hard to go past for battery life and ease of useeBay auction: #124294631547I have used these for Commercial fridge loggers and they work great and very low on battery use.If you want a bit more complexity in your life then ESP 32 board meetseBay auction: #264509390297a Maxim 31865 and a PT100 thermocouple and log it remotely or whatever else you need. Unless you NEED the project buy a solution.

author: daniel444
author_rank: Regular Contributor
timestamp: April 02, 2021, 08:55:10 am
content: "any additional couples are avoided. So if you need new points then buy the right bits."to be clear its the receiving contacts on the pcb board of the meter that have worn out after little useand its designed to hold 2 separate thermocouplesit still holds one thermocuple properly1 to 2c of inaccuracy is fine for my uses , and i really like the ability to put the $2 disposable thermocouple probe into tiny holes , cracks, in soil and stuffi was happy with this meter until the loose contact problem , i think it was around 15 to 25 aud, wouldn't buy again

author: beanflying
author_rank: Super Contributor
timestamp: April 02, 2021, 09:03:28 am
content: The internal contacts 'should' match the material in the plugs if not they create a couple. So Plug and Socket need to match so in your case unlikely you will be able to get a spare.Generally for more accurate ambient temperature measurements PT100 or PT1000's make more sense or there is even some 1 wire Arduino compatible sensors available that can be fed into a Digital pin then read (DSB1820) The sensors are dirt cheapeBay auction: #224379184703and read them with your flavour of Micro ESP or Arduino or ....

author: daniel444
author_rank: Regular Contributor
timestamp: April 02, 2021, 09:16:28 am
content: "The internal contacts 'should' match the material in the plugs if not they create a couple"the k type thermocuple that came with my bm235 seems to have nickel plated contacts that plug into the meter , im confident they will maintain proper tension over time , but it is too good a of a meter to use in the situation im working with

author: beanflying
author_rank: Super Contributor
timestamp: April 02, 2021, 09:21:46 am
content: Not Nickel plated most likely but more like High Chrome for one and Alumel for the other. Have a good trawl of the Omega site sometime and their library/resource sectionhttps://assets.omega.com/pdf/connectors/thermocouple-and-rtd-connectors/GMP.pdf

author: daniel444
author_rank: Regular Contributor
timestamp: April 02, 2021, 10:42:14 am
content: while on topic , i also have this meter , its the cheapest , and i just inspected the contacts and they feel very tight like they wont wear out easilyas you can see i have added an 18605 to it instead of its aaa battery'sit has a mechanical off on switch, there is a version that looks identical apart from it having an electronic switch that causes parasitic drain on the battery's ,i also have that version , it has an auto off function every 30 mins that cant be turned off ,really annoying

author: beanflying
author_rank: Super Contributor
timestamp: April 02, 2021, 10:52:45 am
content: Different option is buy a little stash of these.https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=TempTale+4+USB&_sacat=0I have 10 on the way from Israel via Covid delayed postMy plan is to use them as intended as a throw it in a corner and log for later downloading.