L.R.
Ask your pediatrician about some brands available to consumers. I would bet that the ones the hospital uses are probably hospital-grade, meaning they are much more sensitive and accurate than ones you could buy to use at home -- unless you want to spend a fortune. We tried an ear thermometer (is that what you mean?), a supposedly good brand (Braun) but it never seemed to give the same reading twice. I wasn't comfortable using it, and I just didn't trust it was really able to take a good temperature in the ear.
Our pediatrician, who has written some articles about fever in children so I really trust her on this, told us: The best and most accurate way to take a baby's temperature, or a small kid's, is rectally. Parents hate to do it but it is more accurate than oral or armpit or ear temperatures. It does not cause a child pain. Get a good digital thermometer, get thermometer "covers" (plastic disposable covers that slip over it and slip off to throw away) and KY jelly for lubrication and get used to doing it. (I always used to wear disposable gloves too, to keep things very clean since there's the chance of getting poop on your hands etc. And mark this as a "rectal only" thermometer so no one else in the family sticks in in his or her mouth!) And you don't have to do it forever, thank goodness.
If your kid is older, of course, it's time to teach him how you do an oral temperature (second best for accuracy, according to our doctor) but the child has to be old enough to KEEP the thermometer tip under the tongue and not let it roll around in the mouth, or the temp will not be accurate.
Not what parents want to hear, but there it is. By the way, do look online or ask your pediatrician for the correct "fever readings" for rectal versus oral temps in children; a normal rectal temp tends to be slightly higher than a normal oral temp, so a parent could think "My child has a little fever" based on a rectal temp when actually that temp is normal.