Sous vide rigs may fail, so there should be an alarm when temperature deviates from the set-point.
Lately it happened to me that the FreshMealsMagic triggered the GFCI (ground fault circuit intterrupter) and bath temperature dropped from 49°C to about 48°C during 2h20' cooking. This did not cause me any problem, but if it happens during a 48h-cooking without being noticed, you have to discard your food. It may also happen that a sensor fails or shifts and bath temperature rises or drops.
As my SV-rig resides downstairs in the air-raid-shelter, I looked for a way to baby-sit my SV-rig without going downstairs every hour, and when ordering Nathan's book at Amazon, I also ordered a two-channel remote smoker thermometer Maverick ET-73
which arrived yesterday. It has a channel for the food temperature with a high-alarm and a channel for the oven temperature with high- and low-alarm; the latter can be used to sound an alarm whenever the bath temperature goes outside your set limits.
A known issue with the ET-73 is poor range, especially through walls. I had to place the receiver on the kitchen floor as near to the transmitter as possible to get a signal. So I hacked the receiver and did the Maverick ET-73 Range Modification From LilSmoker
with a small modification shown in the pictures below, soldering the antenna wire to the rear side instead of the front side of the small PCB with the horseshoe shaped circuit board antenna, so the antenna wire does not have to be bent to exit the case. Now the range is sufficient to place the receiver anywhere in the kitchen and have a good signal. It's far from the 100 feet that Maverick claims, but an air-raid-shelter is a bit of a Faraday cage, so I am satisfied with the result. It is possible to make a similar modification on the transmitter, see http://www.instructa...BQ-Thermometer/
, but in my case this was not necessary.
0.7mm SS antenna wire soldered to the rear side of the small printed circuit board
Small PCB replaced after soldering the antenna wire to its rear side
Length of the antenna wire measured from the soldering point has to be exactly 6.5" / 16.5cm which is the quarter wavelength of 433MHz
Small notch in case to accommodate antenna wire
The end result.