Referenced in 1000s of research papers!

The Keithley 6517B Electrometer/High Resistance Meter is the worldwide research laboratory standard for sensitive measurements. With over 60 years of low level measurement expertise, Keithley electrometers provide reliable measurements of current levels down to 10aA (10x10-18A,) charge levels down to 1fC, and the highest resistance measurements available up to 1018Ω. The 6517B also is capable of measuring the largest voltage range - up to 200V - with an input impedance exceeding 200TΩ.

• 10aA (10x10–18A) current measurement resolution
• Measures resistances up to 1018Ω
• <3fA input bias current
• 6½-digit high accuracy measurement mode
• <20µV burden voltage on the lowest current ranges
• Voltage measurements up to 200V with >200TΩ input impedance
• Built-in ±1000V voltage source
• Unique alternating polarity voltage sourcing and measurement method for high resistance measurements
• Built-in test sequences for four different device characterization tests, surface and volume resistivity, surface insulation, resistance, and voltage sweeping
• Optional plug-in scanner cards for testing up to ten devices or material samples with one test setup