Full disclosure: I'm not an engineer. I'm the office administrator for a 170-person manufacturing facility, and I manage roughly $150,000 in lab and test equipment purchases every year. I report to operations and finance, and I work with engineers daily—but I do not pretend to design their tests. What I do is handle the ordering, the vendor calls, the shipping problems, and the calibration schedules. This FAQ is the one I wish I'd had when I started buying Keithley gear.
Here are the questions I hear most from engineers and finance, plus a few I had to learn the hard way. Some are about Keithley multimeters. Some are about function generators, pressure regulators, and even water meters. They all crossed my desk in the last five years, so I'll answer them the way I'd want someone to answer me: no jargon, no vendor script, just what I've learned.
Keithley 2000 vs. Keithley 2002: Which DMM should you order?
What's the difference between a Keithley 2000 and a Keithley 2002?
Engineers ask me this a lot, because the model numbers are close and the price gap is real. The short version: the Keithley 2000 is a 6.5-digit digital multimeter, and the Keithley 2002 multimeter is an 8.5-digit unit. According to Tektronix/Keithley product documentation (Tektronix.com, accessed April 2025), the 2000 is aimed at production, R&D, and education, while the 2002 is built for metrology and calibration labs where lower uncertainty actually matters. The extra digits on the 2002 don't help if your test setup has more noise than the meter's resolution. I've watched procurement get talked into the 2002 by a sales rep who didn't ask what the engineer was actually measuring. Ask the engineer how many digits they truly need and what probe and setup they'll use. At least, that's been my experience with our QC and R&D groups.
What Keithley 2000 multimeter software do I actually need?
If you search the phrase "keithley 2000 multimeter software", you'll see paid driver packages and 'complete solutions' that seem like the only option. Most people don't need them. The 2000 uses SCPI commands over GPIB or RS-232, so you can control it with a VISA runtime and your preferred programming language—Python, MATLAB, LabVIEW—or use Tektronix's KickStart if you want a ready-made interface. The old belief that you need a custom software suite comes from an era when GPIB cards were fussy and drivers weren't standardized. That's changed. Before buying anything, check the manual's SCPI command list and confirm what hardware interface is in your PC. I might be misremembering exact model options, but I've never had to buy a separate third-party program for a Keithley multimeter.
Buying used and knowing when you don't need a Keithley
Is it safe to buy a used Keithley 2000 or Keithley 2002?
Yes, but treat it like an instrument, not a steal. The used market can deliver real savings, but it can also eat them. I once saved $300 on a used Keithley 2000 and then spent $180 on a GPIB controller and cable because the seller didn't include them. The 'budget meter' choice looked smart until the recalibration quote arrived. If you buy used, ask for the original calibration certificate, the current firmware revision, and a list of included accessories. Then add calibration to your budget—not your wish list. A used Keithley 2002 multimeter can be worth it if you're starting a metrology project on a tight budget, but only if the calibration history checks out. At least, that's been my experience with the 2000s and 2002s I've ordered over the years.
Do I need a Keithley if I already have a standard bench DMM?
Not necessarily. If you're checking a 24 V power rail, a standard benchtop meter will do the job. But when you're measuring low currents, low voltages, or small changes in resistance, a Keithley's low measurement noise and repeatability matter. It's not about branding; it's about whether the readings are trustworthy. My job is to ask the engineer, "What measurement uncertainty do you actually need?" before I put anything on a PO. A supplier that says they can handle every application is not being honest. One vendor told me,
"This isn't our strength—here's who does it better."
That earned my trust for the projects where they did excel. I'd rather work with a specialist who knows their limits than a generalist who overpromises. That sounded kinda like a slogan when I first heard it, but after several years of POs, it's just practical math.
Other lab gear on the same purchase order
Can I put a function generator and a pressure regulator on the same PO?
In my office, yes. I've managed orders that included a Keithley DMM, an arbitrary function generator, and a pressure regulator on one line-item list. The purchasing system doesn't care whether it's all from the same supplier, but your test setup does. Be clear why they're together. The function generator matters for signal shape, bandwidth, and output impedance. The pressure regulator matters for flow range, inlet pressure, and wetted materials. If a test-equipment vendor tries to sell you a pressure regulator, ask which materials it's rated for. The difference between a $60 regulator and a $400 regulator is not just margin—it's performance. A brass regulator can be perfect for air and completely wrong for a corrosive process gas. I'd rather buy the regulator from a fluid-control specialist and the Keithley from a test equipment vendor. That's not a rule; it's a boundary. Good vendors don't mind it.
How do I verify a vendor sells genuine Keithley instruments?
I check three things: an authorized distributor letter, a calibration certificate traceable to NIST or equivalent, and the warranty terms. Keithley is part of Tektronix, so I confirm the vendor on Tektronix's distributor page and ask for the exact model number, firmware version, and whether calibration is included in the price. Also, ask about return and calibration turnaround times. Here's something vendors won't tell you: the first quote is rarely the final number for ongoing agreements, but the discount is not what determines your total cost. A meter that sits in a repair queue for six weeks is not a bargain. You might get a great price and lose the savings on the first expedited calibration. I've stopped being shy about asking 'Who does your calibration?' and 'How long does it take?' The best vendors answer without defensive language.
The oddball question: Sensus water meters
How do you read a Sensus water meter, and why is this here?
Because I buy water meters too, and you're not the first person to land here after searching 'how to read sensus water meter'. For the short version: open the lid and let the display wake up. Many Sensus meters have a digital register that cycles through readings; the big number is usually consumption in gallons or cubic feet. If there's a button, press it to move through screens—don't confuse the meter ID or serial number with the reading. If the display is blank, do not guess; call the utility or use the Sensus handheld readout if you have one. The same discipline applies here as to test equipment: know the unit you're reading and know what the number means before you write it down. And yes, I've seen a facility manager assume a 7-digit serial number was the water usage. That's an expensive mistake.
The question I wish I'd asked earlier
What should every buyer ask before purchasing a Keithley?
The question I never asked until I got burned: "What's the calibration turnaround?" The instrument cost is only the first line of the total cost. Annual calibration, shipping, backup instruments, and downtime all add up. We once ordered a Keithley 2000 and then had to wait three weeks for recalibration because we didn't schedule it in advance. That delay cost us more than the small discount we'd negotiated. Now I ask the calibration lab's turnaround time before I place the order. If the vendor can't answer, that tells me everything I need to know. The best laboratories are open about their capacity. Some even offer a loaner program. That's the kind of word that never appears on a spec sheet but makes you look good to your VP.
