6485 Picoammeter The 5-digit Model 6485 Picoammeter combines Keithleys expertise in sensitive current measure- ment instrumentation with enhanced speed and a robust design . With eight current measurement ranges and high speed autoranging, this cost- effective instrument can measure currents from 20fA to 20mA, taking measurements at speeds up to 1000 readings per second . The Model 6485s 10fA resolution and superior sensitivity make it well suited for characterizing low current phenomena, while its 20mA range lets it measure currents high enough for applications such as measuring 4-20mA sensor loops . Although it employs the latest current measurement technology, it is significantly less expensive than other instruments that perform similar functions, such as optical power meters, competitive pico- ammeters, or user-designed solutions . With a price thats comparable to a general purpose DMM, Cost-effective low current the Model 6485 makes picoamp-level measurements affordable for virtually any laboratory or measurement solution p r o duc t ion f lo or . 10fa resolution l ow Voltage burden and Higher accuracy 5-digit resolution While DMMs typically employ shunt ammeter circuitry to measure current, the Model 6485 is a feed- <200V burden voltage back picoammeter . This design reduces voltage burden by several orders of magnitude, resulting in a voltage burden of less than 200V on the lower measurement ranges . The low voltage burden makes up to 1000 readings/second the Model 6485 function much more like an ideal ammeter than a DMM, so it can make current measurements with high accuracy, even in circuits with built-in Model 485 emulation Model 485 Model 6485 very low source voltages . mode Current Ranges 2nA2mA 2nA20mA 200V (1mV on IEEE-488 and rs -232 interfaces successor to the Model 485 Voltage Burden 200V 20mA range) Reading Rate 3/s 1000/s The Model 6485 builds on the strengths of one of analog output Digits 4 5 Keithleys most popular picoammeters, the Model 485, Analog Output Yes Yes offering an additional 20mA measurement range, as well Battery Option Yes No as much higher measurement speeds . With a top speed Storage Buffer 100 points 2500 points of up to 1000 readings per second, the Model 6485 is the fastest picoammeter Keithley has ever made . It offers ten times greater resolution than the Model 485 on every range . A time-stamped 2500-reading data buffer provides minimum, maximum, and standard deviation statistics . A built-in emulation mode simplifies upgrading existing applications originally configured with a Model 485 . This emulation mode makes it possible to control the Model 6485 with any custom code written to control the Model 485 . Refer to the comparison table for additional information . When do you need a picoammeter Measuring low DC currents often demands a lot more than a digital multimeter (DMM) can deliver. Generally, DMMs lack the sensitivity required to measure currents less than 100nA. Even at higher currents, a DMMs input voltage drop (voltage burden) of hundreds of millivolts can make accurate current measurements impossible. Electrometers can measure low currents very accurately, but the circuitry needed to measure extremely low currents, combined with functions like voltage, resistance, and charge measurement, can increase an electrometers cost signifi cantly. The Model 6485 Picoammeter combines the economy and ease of use of a DMM with low current sensitivity near that of an electrometer. 1.888.KEITHLEY (U.S. only) www.keithley.com A Greater Measure of Confidence Measures low currents quickly, accurately, and economically LOW LEVEL MEASURE & SOURCE Measures low currents quickly, accurately, and economically6485 Picoammeter f eatures that Expand Test and Measurement f lexibility ordering Information Scaled voltage analog output. This output allows the Model 6485 to transmit measurement results to devices like DMMs, data acquisition boards, oscilloscopes, or strip chart recorders . 6485 Picoammeter 220V overload protection. This high overload protection and a robust design let the Model 6485 accessories supplied withstand abusive overflows . CaP-18 Protective shield/ One-touch front panel design. Functions can be configured easily with the push of a button, Cap (2-lug) without complicated function menus . 4801 l ow Noise bNC Input Built-in Trigger Link interface. The Trigger Link interface simplifies synchronizing the Model Cable, 1.2m (4 ft) 6485 with other instruments and voltage sources . This interface combines six independent selectable trigger lines on a single connector for simple, direct control over all instruments in a system . RS-232 and IEEE-488 interfaces. These interfaces make it easy to integrate the Model 6485 into automated test and measurement systems . Display on/off switch. For research on light-sensitive components, such as measuring the dark currents of photodiodes, the front panel display can be switched off to avoid introducing light that could significantly reduce the accuracy of the results . REL and LOG functions. The Model 6485 can make relative readings with respect to a baseline value or display the logarithm of the absolute value of the measured current . Resistance calculations. The Model 6485 can calculate resistance by dividing an externally sourced voltage value by the measured current . Rear panel BNC inputs. Inexpensive, easy-to-use BNC cables can be employed, rather than more expensive triax cables . aPPl ICaTIo Ns aCCEssor IEs aVaIl abl E sEr VICEs aVaIl abl E beam monitoring and radiation 6485-3Y-EW 1-year factory warranty extended to 3 years from monitoring Cabl Es date of shipment 4802-10 Low Noise BNC Input Cable, 3m (10 ft) l eakage current testing in C/6485-3Y-ISO 3 (ISO-17025 accredited) calibrations within 3 4803 Low Noise Cable Kit years of purchase* insulators, switches, relays, and 7007-1 Shielded IEEE-488 Cable, 1m (3 . 3 ft) *Not available in all countries other components 7007-2 Shielded IEEE-488 Cable, 2m (6 . 6 ft) 7007-4 Shielded IEEE-488 Cable, 4m (13 . 1 ft) sEM beam current 7009-5 RS-232 Cable measurements 7754-3 BNC to Alligator Cable, 0 . 9m (3 ft) Galvanic coupling 8607 Banana Cable set for Analog Output measurements 8501-1 Trigger Link Cable with Male Micro-DIN Connectors at each End, 1m (3 . 3 ft) o ptoelectronic device testing 8501-2 Trigger Link Cable with Male Micro-DIN Connectors at and characterization each End, 2m (6 . 6 ft) 8503 DIN-to-BNC Trigger Cable o ptical fiber alignment aDaPTErs Circuit test and analysis in CS-565 BNC Barrel DCl f circuits 7078-TRX-BNC Female BNC to 3-Slot Male Triax for connecting BNC cable into triax fixture sensor characterization r aCK Mou NT KITs I-V measurements of 4288-1 Single Fixed Rack Mounting Kit semiconductors and other 4288-2 Dual Fixed Rack Mounting Kit devices GPIb INTErfa CEs KPCI-488LPA IEEE-488 Interface/Controller for the PCI Bus Nanoelectronic device KUSB-488B IEEE-488 USB-to-GPIB Interface Adapter characterization Capacitor leakage Teaching labs 1.888.KEITHLEY (U.S. only) www.keithley.com A Greater Measure of Confidence Measures low currents quickly, accurately, and economically LOW LEVEL MEASURE & SOURCE Measures low currents quickly, accurately, and economically