I recently bought a used Fluke 87V off eBay. Thinking it might be handy to use the temperature measurement capabilities, I also bought a Fluke 80AK-A thermocouple adapter, which arrived here yesterday, and a generic K-type thermocouple, which arrived today. Plugged the thermocouple into the 80AK-A, and the 80AK-A into the 87V, and set the 87V to the temperature mode--it says "OPEN". Do I have a bad thermocouple, a bad adapter, or am I doing something wrong?