This blog posting will concentrate on the unboxing process, providing our first introduction to the Keithley 2450 SMU.
The unit comes inside a long cardboard box, with the distinctly Keithley logo in the top left corner of the side of the box. It also clearly proclaims it to be a Tektronix company, which it has been since 2010.
The side of the box has labels which provide more details on the unit inside. This unit claims to be manufactured 19th December 2019, making it a relatively recent unit. The label has a number of regulatory approvals including the Australian RCM making it approved for use in Australia. It also carries the Proposition 65 warnings for the state of California in the USA. Prior to receiving the unit, it seems this unit had been unsealed at one point (based on seeing the break in the red packing tape), which is perhaps not unusual for a RoadTest unit.
The unit is nestled inside two large foam inserts which elevate it from all sides of the sturdy double-walled cardboard box. Accessories are packaged in their own zip-lock style bag, placed above the unit. This is a simple packaging arrangement, but has served the unit well in its trip from the USA to Australia.
Removing the unit from the end-pieces, I was surprised to see it was shipped without being in its own bag or cover. Instead, the unit was left open, with the exception of the front of the LCD which has a protective film covering.
Removing the film reveals a clean but slightly “spotted” front window in front of the LCD which dominates most of the front panel. The power switch is a hardware push button in the bottom left, while the remainder of the keys are of the “rubberised” sort you might find on remote controls and calculators. A USB-A port sits just above the power button, allowing users to export data and screenshots. The LCD screen features capactive sensing touch, allowing for direct interaction, with some actions instead initiated by the eight rectangular buttons which are broken into two groups on either side of the display. A rotary encoder knob with push selection is used as another form of user interface, it too being covered with a ribbed rubber finish. The output on/off is controlled by a soft-key in the top right, which is translucent and backlit to indicate channel state, while a terminal switch button is located near the bottom right to switch between the 4mm safety banana jacks on the front and the triaxial rear outputs which are guarded and more suitable for very low current measurements.
The rear of the unit is adorned with a variety of connections and ventilation grilles. The power input is through a fused IEC connector, accepting world-wide voltage without the need for manual voltage selection. Remote control connection is available via LAN, USB, TSP-Link and GPIB as standard. A DE-9 digital I/O port is also provided for trigger in/out for use with handler systems or for synchronisation with other instruments. An interlock input is provided for safety – the unit will limit output voltage unless the interlock safety circuit is closed and will cut the output whenever the interlock changes states.
Four triaxial connections are provided for the rear output, providing a guarded output for precise low-current measurements. Finally, chassis and mains ground screw connections are provided.
The top and bottom of the unit features ventilation grilles. The underside has a sticker with various approvals and patent notices. The unit is Made in China.
A plastic combination stand and handle is provided. By default, it is tucked underneath the unit, allowing the unit to stand level on its rubber surrounds at each end. The stand can be positioned to prop the unit up, providing a more comfortable viewing angle for use at the bench. It can also be positioned across the middle of the front panel for use as a handle. Finally, it can be folded all the way over the top of the unit. It does not seem particularly sturdy, although it doesn’t really have to be because the instrument is not all that heavy. The sides of the unit also feature ventilation grilles.
The rubber end surrounds can be removed. This may be necessary to install the unit into an optional rack-mount unit.
One downside that I spotted immediately was that the chassis was lighter than I had imagined and seemed to have a significant amount of flex. This shouldn’t impact performance directly, but does not inspire much in the way of confidence about build quality.
Aside from the unit, there is some paperwork included. This includes some safety notices, information about where to find the downloads, information about the included test leads, a plastic-spiral bound colour quick-start guide and a Keithley KickStart CD dated from November 2013. The quick-start guide is a nice touch – it’s an easy read and enough to get you going without costing too much paper. The CD is very much likely to be out of date, as KickStart has changed a lot in the intervening years. Unlike some other instruments I’ve received, this unit does away with the calibration certificate and report entirely. I’m not sure if this is the case for units received through ‘retail’ channels, but the last calibration date is stored in the unit if that’s any consolation.
Also included is an Ethernet cable, a USB A to B cable, a US power lead, interlock connector and Keithley 4mm safety test lead kit (P/N: 012173001). The inclusion of the US power lead is perhaps appropriate for the US market, where this unit came from. I assume that locally sourced units will have the correct power lead supplied. That being said, the inclusion of a USB A to B cable and test-lead set is generous.
The included Ethernet cable is a cross-over type and was specially included due to the TSP-Link feature which requires such a cable (from my understanding). However, it can also be used for LAN connectivity.
The design of the interlock connector accepts three wires from the rear and is a snap-down crimp type connector. These are easy to terminate, however, such connectors may not be so reusable. The three connections supply the interlock signal, ground and power.
The test leads are also rather interesting. They consist of a pair of 1000V 20A CAT III rated shrouded banana to banana leads with a generous 1.2m length and a “plug in” set of test hooks. The cable on these leads is insulated with silicone rubber resulting in a surprisingly thin and flexible test lead. The only downside so far is that the plugs themselves can be a bit “tight” – I suppose this is not unusual for fresh leads.
The spring-loaded test hooks have a small amount of metal protruding in their retracted position, doubling up as test probes. The spring action makes it simple to clip onto exposed wires for a temporary connection.
Definitely a decent set of accessories to have supplied with the unit, although it might have been nicer if there was something with a four-wire Kelvin connection to better illustrate what the 2450 is fully capable of without adding too much in the way of cost. During the process of scoping things out, I discovered that high-voltage triaxial cable, connectors and test fixtures are pretty expensive by comparison – so it’s nice that the 2450 gives you a choice between banana plugs and triaxial connectors should you need it.
The unit arrived safely from the USA packaged in a distinct, Keithley-branded double-walled cardboard box. Inside, the accessories are stored in their own zip-lock style plastic bag and the unit is bare (with the exception of an LCD protection cover film), supported at its ends by foam inserts which provide clearance around the unit. This minimal packaging philosophy is more environmentally friendly and seems to be sufficient to keep the unit safe.
The unit’s front panel is dominated by a 5” colour LCD with capacitive touch, with supplementary inputs supplied by eight rectangular rubberised buttons flanking both sides of the display and a push-rotary encoder. There is a hardware power button, USB-A socket for exporting data and screenshots, output on/off and front/rear terminal control button. Front panel outputs are in the form of five safety banana sockets. The rear of the unit offers a fused universal-voltage power input, remote control interfaces including LAN, USB, TSP-Link and GPIB, digital I/O, interlock connection and guarded outputs especially suited for low-level measurements in the form of four triaxial connections. The unit features air vents on all sides except the front and has a plastic carry handle that doubles as a stand, although this doesn’t seem particularly sturdy and can only be set in one of four positions. The unit was lighter than expected and its metal casing exhibited some amount of flex. The unit itself was manufactured 19th December 2019 in China and carries the Australian RCM, making it approved for use in Australia.
The unit has a rather generous accessory bundle which includes safety notices, information about where to find the downloads, information about the included test leads, a plastic-spiral bound colour quick-start guide, Keithley KickStart CD (which is out of date), cross-over Ethernet cable (for LAN or TSP-Link), a USB A to B cable, a US power lead, interlock connector and Keithley 4mm safety test lead kit (1.2m, surprisingly flexible for its 1000V/20A CATIII rating). Unlike some other instruments I’ve received, this unit does away with the calibration certificate and report entirely. If I had any particular wish, it would be for something with a four-wire Kelvin connection to better illustrate more of what the 2450 is capable of without adding too much in the way of cost.
This blog is part of the Keithley 2450 SMU with I-V Tracer RoadTest.