The 6485 is a picoammeter, a meter for very small currents, and it doesn't source anything. We list it with the SourceMeters because that's where low-current bench gear lives here. It's the successor to Keithley's popular Model 485. Keithley added a 20 mA range, ten times the resolution on every range, a 2,500-reading buffer and up to 1,000 readings a second, and kept a 485 emulation mode so old programs still run. It's a feedback ammeter, so the voltage drop it adds to your circuit stays under 200 µV, and it resolves 10 fA on the 2 nA range. The input is a plain BNC on the back, so ordinary low-noise BNC cable works instead of triax. Tektronix still sells it. If you need a built-in voltage source, look at the 6487 instead.
Options and accessories
Check the listing photos and the rear panel against this list, and ask the seller about anything you can’t see. A missing option or probe should come off the price.
At picoamp levels the cable and connector matter, so a damaged input cable or a bent BNC adds noise and offset. New units shipped with a 4801 low-noise BNC cable and a CAP-18 shield cap, so check whether they're included.
New to used bench gear? How to check used test equipment covers self-tests, fuses, the voltage selector and shipping, and what “calibrated” means in a listing.
Buying guide
We'd buy next.day.automation's 6485 at $1,850 delivered with free shipping, near the $1,790 median, from a US dealer whose photo shows the display lit. There are at least 84 for sale, mostly from China resellers asking about $1,330–1,800 delivered, and several share titles and watermarked photos (LEYPIN, Aimevo) across accounts, so the meter pictured may not be the one you get. The other US sellers here ask $2,024–2,543 delivered. None is titled with the 4801 low-noise BNC cable or CAP-18 shield cap that came with it new, so budget for low-noise cable, and ask for a photo with zero check on and the input capped, settling near zero on the 2 nA range, plus the label to rule out a 6487. Skip yuajjcpu's $5,623 ask, about 3.1 times the median.
$1,789.89est. delivered
The lowest delivered 6485 we'd consider, at $1,790, with the seller's own photo. It ships from China and the photo shows it switched off, so ask for a photo of this unit with its serial and the zero check running.
1 PCS Keithley 6485 Picoammeter/dm
$1,850.00delivered
A US dealer's 6485 at $1,850 delivered with free shipping, titled with its ranges and IEEE-488 and RS-232, and the photo shows the display lit. No cable is titled, so add a low-noise BNC cable to your budget.
Keithley 6485 Picoammeter, 2nA-20mA Range, 10fA Resolution, IEEE-488, RS-232
Delivered prices include shipping as eBay quoted it to a US address on Oct 14, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 14, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$1,789.89est. delivered
$1,589.89 + $200.00 shipping
Buy It Now$1,589.89
Good buy
Ships from China, shown switched off. Ask for a photo of the actual unit with its serial.
Seller: dmm-test
100% positive
Used$1,850.00delivered
$1,850.00 · free shipping
Buy It Now$1,850.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
US dealer, free shipping. Photo shows the display lit; no cable titled.
Seller: next.day.automation
99.9% positive
Used$2,024.04est. delivered
$1,999.20 + $24.84 shipping
Buy It Now$1,999.20
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
US seller with a plain title. Ask about the cable and for a zero-check photo.
Seller: opticsguyca
100% positive
Used$2,542.77est. delivered
$2,495.00 + $47.77 shipping
Buy It Now$2,495.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
US dealer, near the top of the band. No cable titled.
Seller: alltest_instruments
99.5% positive
Used$1,425.00delivered
$1,425.00 · free shipping
Buy It Now$1,425.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Check the seller
Title shared with other accounts, and 98.2% feedback. Ships from China, shown switched off.
Seller: pass-test
98.2% positive
Used$1,427.00est. delivered
$1,327.00 + $100.00 shipping
Buy It Now$1,327.00
Check the seller
LEYPIN watermark seen on other sellers' photos, and a copied title. Ships from China.
Seller: yiso-test
99.4% positive
Used$2,600.00est. delivered
$2,400.00 + $200.00 shipping
Buy It Now$2,400.00
Check the seller
Photo carries an Aimevo watermark seen on other accounts, and the title is shared. Ships from China.
Seller: dearne-66
99.1% positive
Used$5,622.75delivered
$5,622.75 · free shipping
Buy It Now$5,622.75
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Priced high
About 3.1 times the median for a unit titled used and working.
Seller: yuajjcpu
100% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 14, 2026.
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