I wonder if there is anything special about the encapsulated external temperature sensor sold in OEM shop? I have several of them already, purchased from China. The sensor is not detected with my EmonTH 1.5. All I can get is zeroes.
Do your sensors have any markings on them - do you have a link to where you found them or a photograph? How have you connected them to your emonTH?
I have a bunch of ready-made sealed sensors with a 3-foot wire. No markings except the colour coding of wire leads. They actually look very much like the picture in the shop.
I use them with Raspberry Pi and DS2490 USB adapters, and they work like a charm.
The sensors are connected to the terminal onboard EmonTH as instructed in the wiki:
https://wiki.openenergymonitor.org/index.php/EmonTH_V1.5#DS18B20_Temperature_Sensor
Is the sensor definitely a DS18B20? To answer your question, the encaspulated sensors in the OpenEnergyMonitor Shop are not customized.