Order & Collect
Collect your order for free at one of over 2200 stores
£ or free when you spend £45 or more
Next Day Delivery
£ - place before 7pm for delivery the next day. Excludes weekends
Named Day Delivery
£ - choose a weekday within the next 14 days for delivery
£ - usually delivered between 7am - 1pm
For more information see our delivery help or view our returns policy .
There are, however, two catches to be aware of. One, the Kinsa Smart Stick has no display of its own, so you can only use it in conjunction with a smartphone that has the matching app. Two, along with the user concerns about accuracy that seem to accompany all digital stick thermometers, many note that this thermometer isn't compatible with every device, so check the manufacturer's compatibility list before you buy. In particular, if you own an iPhone 7 or 7 Plus -- neither of which has a headphone jack -- you're out of luck until Kinsa finds a way to make their Smart Stick thermometer work with Apple's headphone-to-Lightning adapter.
There are several principles on which empirical thermometers are built, as listed in the section of this article entitled "Primary and secondary thermometers". Several such principles are essentially based on the constitutive relation between the state of a suitably selected particular material and its temperature. Only some materials are suitable for this purpose, and they may be considered as "thermometric materials". Radiometric thermometry, in contrast, can be only slightly dependent on the constitutive relations of materials. In a sense then, radiometric thermometry might be thought of as "universal". This is because it rests mainly on a universality character of thermodynamic equilibrium, that it has the universal property of producing blackbody radiation.