"at a proper temperature" is correct and usable in written English.
It is typically used to describe something that is at the correct temperature for a specific purpose or requirement. Example: "The cake was baked at a proper temperature, resulting in a perfectly moist and golden crust."
Those who also operate restaurants typically bring prepared food to a cart equipped to keep it at a proper temperature.
In other words, no matter what you order in a restaurant, if it's not kept at a proper temperature and protected from contamination, you're at risk.
For this last method, the company has eight available cold chambers, each one defined to preserve a specific group of products at a proper temperature.
Both nitrogen and sulfur dopants were introduced into the anatase TiO2 lattice to replace a small portion of oxygen by calcinating the as-prepared TiO2 nanocrystals with thiourea at a proper temperature, which largely enhanced their light absorption in the visible-light range.
Set the heater at a proper temperature.
If you're able, you may also want to get a heat pad to go under your seed trays to keep the soil at a proper temperature.
It is shown that the blanket module materials remain within a proper temperature range only at shallow incident angle if the width of EUROFER is reduced at list twice compare with the reference case.
The fines are issued to businesses for a range of violations, some big, some small: failing to refrigerate food in a restaurant at the proper temperature, for example, and failing to properly advertise return policies.
Krug and Berluti have conceived of an ultra-luxe mode for safely transporting, (at the proper temperature no less), a bottle of Champagne (ideally Krug of course) in style.
To help prevent premature opening, though, the container has a spot of heat-reactive dye on the label that turns a different color at the proper temperature.
