# Temp inaccuracy is not linear **URL:** \ **Category:** Anova Support\ **Created:** [November 18, 2014, 6:16pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129 "2014-11-18T18:16:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 18, 2014, 6:16pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/1 "2014-11-18T18:16:54Z")
I noticed the inaccuracy is not linear, for example, in the mid 140’s range it’s off by about 1.8 or 1.9 +/-, whereas in the low 180’s range it’s off by about 2.5 +/-. How does recalibration by app work? I would suggest that If it’s simply adding/subtracting a fixed number behind the scene to/from the temp display then it’s not good enough, please prove me wrong. Would you recalibrate it differently if I ship it back? For example, will you physically/mechanically tweak something, replace a defective component? ---
**Author:** ![vtemkin](https://avatars.discourse-cdn.com/v4/letter/v/c67d28/32.png) [@vtemkin](https://community.anovaculinary.com/u/vtemkin)\ **Post date:** [November 18, 2014, 7:57pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/2 "2014-11-18T19:57:30Z")
I afraid, app calibration is just that: adding/subtracting fixed number - at least the calibration factor is just a signed number. (That’s in Anova interface I use for my upcoming app.) With such variance I’d say try to ship it back (may be after the current support/shipment craziness will subside). [I am not speaking for Anova.] ---
**Author:** ![Anova](https://avatars.discourse-cdn.com/v4/letter/a/b487fb/32.png) [@Anova](https://community.anovaculinary.com/u/Anova)\ **Post date:** [November 18, 2014, 8:01pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/3 "2014-11-18T20:01:22Z")
Hi @canugghead‌, I’m sorry your having calibration and temperature issues. Let’s get this cleared up. Can you tell me what you are using to compare the temperature variants? As far as calibration via the app, the app will allow you to adjust calibration on their own. You will be able to go in and adjust calibration of your unit if necessary. However if it is a hardware issue, we will need to get the unit back and swap out with a functioning one if it cannot be fixed. ---
**Author:** ![sousevide](https://avatars.discourse-cdn.com/v4/letter/s/a6a055/32.png) [@sousevide](https://community.anovaculinary.com/u/sousevide)\ **Post date:** [November 18, 2014, 8:08pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/4 "2014-11-18T20:08:28Z")
Well just because the adjustment command input is a fixed offset doesn’t mean it will be applied as a constant adjustment over the entire range. Because you apply the adjustment at a specific temperature, it could actually support multi-point calibration behind the scenes. It also depends on how the firmware handles the nonlinearity of the sensor (curve fitting or lookup table) and how that is remapped to fit the corrected data point(s). But a programmer would have to answer this. ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 18, 2014, 10:31pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/5 "2014-11-18T22:31:36Z")
@Anova‌ I compared against two Thermapens. Can mail you some photos if you like. ---
**Author:** ![Stephen\_Svajian](https://sea2.discourse-cdn.com/flex016/user_avatar/community.anovaculinary.com/stephen_svajian/32/6222_2.png) [@Stephen\_Svajian](https://community.anovaculinary.com/u/Stephen_Svajian)\ **Post date:** [November 19, 2014, 1:58am UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/6 "2014-11-19T01:58:26Z")
@canugghead‌ Please send photos. You can also post photos in here. ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 19, 2014, 2:42am UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/7 "2014-11-19T02:42:24Z")
How do I post photos here? ---
**Author:** ![tjal](https://avatars.discourse-cdn.com/v4/letter/t/5e9695/32.png) [@tjal](https://community.anovaculinary.com/u/tjal)\ **Post date:** [November 19, 2014, 2:57am UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/8 "2014-11-19T02:57:32Z")
Here are the reading I’m getting: [Dropbox - 2014-11-15.jpg - Simplify your life](https://www.dropbox.com/s/vy3kkhi4ubio9bf/2014-11-15.jpg?dl=0) As well, I can’t get the unit to hit 130F with a cover, it gets to 129.7F and maxes out. If I turn it off, it shows 130.3F. Anyone else having this issue? While it’s close enough, wondering if it’s standard. ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 19, 2014, 3:39am UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/9 "2014-11-19T03:39:18Z")
[![](https://dl.dropboxusercontent.com/s/pb4iu17poak6pv2/IMG_1598.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/pb4iu17poak6pv2/IMG_1598.JPG?dl=0) [![](https://dl.dropboxusercontent.com/s/411ewjclazecz7n/IMG_1599.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/411ewjclazecz7n/IMG_1599.JPG?dl=0) [![](https://dl.dropboxusercontent.com/s/euvr8helvhk1r93/IMG_1605.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/euvr8helvhk1r93/IMG_1605.JPG?dl=0) ---
**Author:** ![Stephen\_Svajian](https://sea2.discourse-cdn.com/flex016/user_avatar/community.anovaculinary.com/stephen_svajian/32/6222_2.png) [@Stephen\_Svajian](https://community.anovaculinary.com/u/Stephen_Svajian)\ **Post date:** [November 19, 2014, 6:03pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/10 "2014-11-19T18:03:41Z")
@canugghead‌ Thanks for that. Could you please contact [support@anovaculinary.com](mailto:support@anovaculinary.com) to schedule a return? ---
**Author:** ![Stephen\_Svajian](https://sea2.discourse-cdn.com/flex016/user_avatar/community.anovaculinary.com/stephen_svajian/32/6222_2.png) [@Stephen\_Svajian](https://community.anovaculinary.com/u/Stephen_Svajian)\ **Post date:** [November 19, 2014, 6:05pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/11 "2014-11-19T18:05:53Z")
@tjal‌ Could you also please contact [support@anovaculinary.com](mailto:support@anovaculinary.com) to schedule a return? ---
**Author:** ![elangomatt](https://avatars.discourse-cdn.com/v4/letter/e/b9bd4f/32.png) [@elangomatt](https://community.anovaculinary.com/u/elangomatt)\ **Post date:** [November 19, 2014, 6:11pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/12 "2014-11-19T18:11:34Z")
@canugghead‌ Does it make me a math geek if I’m curious about what the curve would look like if you graphed them? I haven’t tested my Anova temp differential across multiple temps at all but I might just have to so I can see if the inaccuracy is constant or not. ---
**Author:** ![mspeleoto](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@mspeleoto](https://community.anovaculinary.com/u/mspeleoto)\ **Post date:** [November 19, 2014, 6:20pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/13 "2014-11-19T18:20:37Z")
@elangomatt‌ Yes, but we’re all geeks here anyway. I’d be interested in seeing that curve. ---
**Author:** ![Stephen\_Svajian](https://sea2.discourse-cdn.com/flex016/user_avatar/community.anovaculinary.com/stephen_svajian/32/6222_2.png) [@Stephen\_Svajian](https://community.anovaculinary.com/u/Stephen_Svajian)\ **Post date:** [November 19, 2014, 6:28pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/14 "2014-11-19T18:28:30Z")
@canugghead‌ Could you please test the temperature of the water right next to the circulator? It takes a minute for the temp to stabilize through the entire pot. ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 19, 2014, 9:54pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/15 "2014-11-19T21:54:01Z")
> @canugghead‌ Could you please test the temperature of the water right next to the circulator? It takes a minute for the temp to stabilize through the entire pot. Stephen, your help is much appreciated. Actually before I took each photo, the circulator has been running for a while. I also tested the Thermapens at various locations next to, near, and around the circulator, with very similar readings. I’ll try again if I get a chance. Also, I can test my second Anova (red) when it arrives in December and compare. If I return the unit, what can/will Anova do for me? Since I’m in Canada, even though you cover $hipping both ways, I’m afraid I still have to pay taxes and Fedex handling fees again? It’ll probably help if you ship back by USPS as many Canadians have requested, and also declare clearly on the customs form that it’s a warranty repair/replacement, hopefully I won’t have to pay again. ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 19, 2014, 10:06pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/16 "2014-11-19T22:06:14Z")
One of my friends also received his on the same day, his temp is dead on as it should. As you can see, his Thermapen is not right next to the circulator. [![](https://dl.dropboxusercontent.com/s/wu7ftbaz6j3to8d/dead%20on.jpg?dl=0) ](https://dl.dropboxusercontent.com/s/wu7ftbaz6j3to8d/dead%20on.jpg?dl=0) ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 19, 2014, 10:18pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/17 "2014-11-19T22:18:11Z")
They almost agree in boiling water though… [![](https://dl.dropboxusercontent.com/s/5fku4xbbny0dh75/IMG_1594.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/5fku4xbbny0dh75/IMG_1594.JPG?dl=0) [![](https://dl.dropboxusercontent.com/s/gin1bk5uca42xen/IMG_1596.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/gin1bk5uca42xen/IMG_1596.JPG?dl=0) ---
**Author:** ![canugghead](https://avatars.discourse-cdn.com/v4/letter/c/ba8739/32.png) [@canugghead](https://community.anovaculinary.com/u/canugghead)\ **Post date:** [November 20, 2014, 7:10pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/18 "2014-11-20T19:10:33Z")
> As promised, picture taken long after system was stabilised, Anova current temp = set temp = 148.0 Thermapen (almost touching Anova) = 146.1 [![](https://dl.dropboxusercontent.com/s/cnpdnf04lzkb6e0/IMG_1623.JPG?dl=0) ](https://dl.dropboxusercontent.com/s/cnpdnf04lzkb6e0/IMG_1623.JPG?dl=0) ---
**Author:** ![mmm](https://avatars.discourse-cdn.com/v4/letter/m/0ea827/32.png) [@mmm](https://community.anovaculinary.com/u/mmm)\ **Post date:** [December 15, 2014, 12:49am UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/19 "2014-12-15T00:49:45Z")
Is there an update on this. I have found the same general pattern as the OP. The temperature is about one degree off at lower temps (±120). The gap rises to the 1.5 degrees by the 140s and by 180 the temperature is off by 2.5 degrees. I have verified this using three different thermometers; a thermapen, a thermopop and a traditional leave-in probe. All three of these external thermometers match each other. I know that it has been stated that the app will allow for calibration, but I have yet to see the answer about this sort of difference. Will the app provide a simple offset of a fixed number of degrees or will it provide for this sort of varied difference? ---
**Author:** ![brecht](https://avatars.discourse-cdn.com/v4/letter/b/ecc23a/32.png) [@brecht](https://community.anovaculinary.com/u/brecht)\ **Post date:** [December 17, 2014, 5:08pm UTC](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129/20 "2014-12-17T17:08:43Z")
I’m having a similar problem, the temp seems to be off by about 4°C (compared to two different thermometers which both pointed to the same temp; unfortunately the Anova didn’t) . Hope the app will solve this. [Next page](https://community.anovaculinary.com/t/temp-inaccuracy-is-not-linear/129.md?page=2)