Hi, I am new to four point probe measurements and I have a question. I've deposited 500 nm of Ni on glass substrate to check out the equipment we bought. When I measured its sheet resistance the display showed 13.56 mohm/sqare for 5 mA current. To check out the measurement I multiplied the sheet resistance with the coating thickness which gave about 1/10 of Ni's bulk resistivity (96.3 nohm.meter). I couldn't figured it out if it's a faulty measurement or is there a logic I am missing. Any help would be appreciated. thanks.