What I do to check this type of sensor is to 1st get an old female connector from the wrecker. Strip the wires & make a couple of loops & solder. Plug the sensor on to the connector, tie both the thermometer probe & sensor together to an old welding rod, coat hanger, something firm & vertical. Place in an old soup can (clean) place a lid w/ a hole in it (so the leads pass thru. & fill w/ water so both sensor & thermo are immersed but not the connector. I use an old lab 115V hot plate (cheap & great control, good for thermostats also). With the connector loops out of the can you can quickly test all resistances.
Total cost for me to setup was about $10.00 & good for life.