Yes, you do need to check your ground connection! Use this device [https://www.homedepot.com/p/Power-Gear-3-Wire-Receptacle-Tester-50542/206212329?|HomeDept - 3-Wire Receptacle Tester] and you will need to test the outlet again if you go to another work area. You also should check your breaker panels connection to ground.
* Clean the area of un-needed stuff
* Make sure you have adequate lighting at the work area
* Place the antistatic mat down on the surface you are planing on work at
* Place the cord snaps to the side, the back one for the outlet lead, the front one for the wrist strap (if the mat has one, if not use the alligator to banana clip onto the mat
* Test the outlet with a receptacle tester
* Plug in the 3 prong ground adapter
* Plug in the banana plug of the mat cord into the adapter
* Take your system, tools & any parts placed on the mat.
* Sit down at the desk, place the wrist strap onto your wrist - '''Wait!''' At least 30 sec’s to allow your body to discharge
Start the job!
If you leave make sure everything is on the mat that is static sensitive, When you sit back down don’t touch anything other than the wrist strap, put it on and again '''Wait!''' At least 30 sec’s to allow your body to discharge before starting up again.