Keithley 2560 Error in Low Curr free download

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A G R E AT E R M E A S U R E O F C O N F I D E N C E B. Keep the insulator clean--Oils and salts from the skin can degrade insulator per- formance, and contaminants in the air can be deposited on the insulator surface, reducing its resistance. Clean the insula- tor with a cotton swab dipped in metha- nol. After cleaning allow the insulator to dry for several hours at low humidity be- fore use, or dry it with dry nitrogen gas. Problem: Errors C. Guard the insulator--Use a driven guard that surrounds the insulator; a guard that in Low Current surrounds the entire high impedance area is even better. Measurements Potential Cause: Meter Bias Current Ammeters have some small current that flows when the input is open. One of the most common causes of error 3. Water Absorption--Leakage depen- Remedy when measuring low currents (<1nA) is off- dent on the amount of water that has Choose an electrometer or picoammeter set current, which can come from the test been absorbed by the insulator. to minimize meter bias current. Meter bias setup