Test Equipment you didn't know you needed

[forrestc]

There are a few pieces of test equipment we all know we need or want....  DMMs, Power Supplies, Oscilloscopes, maybe even a signal generator or similar.   

This question is about none of those things.   This is about those pieces of test equipment that you didn't know you needed, but once you found out about them, they've become an important part of your arsenal. 

I'll start with mine.   The AIM TTI i-Prober 520.  Dave talked about this in EEVblog #296.   I'll post the link to the video below, but this one piece of test gear has saved me quite a bit of time tracking down shorts on PCBs, not to mention eliminating the need to cut traces at times to narrow down the portion of the board where the short occurred.   I only wish I had known about this earlier.

Which brings me to my question.... I'm pretty certain this isn't the only piece of kit out there which I am blissfully unaware of, but would find very helpful on the bench.  I would love to find out what other EEVblog forum members have found which falls into this same category.   So, what is your favorite slightly off-mainstream test gear?

The Video:

[casinada]

I  wish it wasn't that expensive. 

[JLNY]

I Don't know if it counts as a true piece of "test equipment", but one of those cheap little component testers from ebay that can read capacitor ESR has proven to be a real lifesaver when debugging old/leaky capacitors in power supplies, as well as many other applications.

[forrestc]

I  wish it wasn't that expensive. 

No kidding.  It took me a while to decide I needed it.  After about the 2nd or 3rd board I destroyed in the process of tracking down a short, I decided that it would probably save me more money over the long run.

[Someone]

This is about those pieces of test equipment that you didn't know you needed, but once you found out about them, they've become an important part of your arsenal.

So, what is your favorite slightly off-mainstream test gear?

Curve tracer/SMU, always knew what they were for but didn't realise their day to day value until I had a spare one around the lab.

[tautech]

Had them a while now 'cause everything now is SMD.

Smart Tweezers.
http://www.smarttweezers.com/st5s/

Mine are older ST3, powered with LR44's.
Easily in my top 5 pieces of gear as I use them on nearly all fault finding/component testing, TH and SMD.
ESR tests too.

Indispensable. 

[WastelandTek]

quoted from my Tek 5000 thread

I became addicted to the dual port network analyzer some years ago when I had a buddy that worked at a VERY swank lab and we could go in the night and use the equipment.  Once you have used one, doing any real RF work without seems like stumbling around in a dark cave with a book of paper matches as opposed to exploring with a nice big torch.  In the pic above, the system is displaying the S11 and S21 of a typical RF low pass filter simultaneously.  You can tweak on the DUT and observe the effects in real time.  This is VERY handy for developing an intuitive sense for circuit behavior.  Once you have used one it is really frustrating to go back to doing it any other way.

[HighVoltage]

Keithley 2450 and 2460 SMU !
They are expensive but once you have them you don't want to miss them anymore.

[alm]

I'll start with mine.   The AIM TTI i-Prober 520.  Dave talked about this in EEVblog #296.   I'll post the link to the video below, but this one piece of test gear has saved me quite a bit of time tracking down shorts on PCBs, not to mention eliminating the need to cut traces at times to narrow down the portion of the board where the short occurred.   I only wish I had known about this earlier.

The old HP 547 Logic current tracer can sometimes do the same job for less 10% of the price. Limitations is that it is qualitative only (proportional lamp with variable offset) and it requires a square wave signal (designed for logic pulses), which means it does not work well for power rails on a populated PCB (all decoupling caps appear as shorts) and obviously ground planes (but neither does the TTI if you look at Dave's failed Lecroy repair attempt video).

A clamp-on current probe, AC only or AC+DC, can be very useful for power supply problems. As is a high voltage differential probe. All kinds of clips to hook up DMM and scope probes to component leads. From those designed for leads with several mm pitch (e.g. TO-247) down to 0.5 mm pitch. For IC leads, I like the discontinued Tektronix P6561/2/3A probes. Much smaller and lighter than the old-fashioned 5mm scope probes, so you can hang them from an IC pin without issues. Better for signal integrity than using wires (inductance!) to extend a probe. Obviously much more fragile due to their tiny size. Sometimes show up on eBay for much less than active probes.

An SMU was already mentioned multiple times. It is basically a Swiss army knife of DC and can do any combination of DMM, voltage source and current source. If you are on a limited budget, consider the old Keithley 236/237/238. Accuracy and ranges are surprisingly close to modern 2450 models.

[all_repair]

I  wish it wasn't that expensive. 

No kidding.  It took me a while to decide I needed it.  After about the 2nd or 3rd board I destroyed in the process of tracking down a short, I decided that it would probably save me more money over the long run.

IR camera you shall also need.  It is used as frequent as multimeter in my work bench now.

[PA4TIM]

For me that same iprober-520. The HP-547 is besides rare also AC only.

I have a Tek 576 curve tracer and I now use that a lot. At first I wanted one because it was a cool piece of test gear but the more you learn to use it, the more you do with it. I use it for transistors and fets but also to test MOV's, leakage, test relais, measure the Ri of a battery, use it as a load, charge batteries, signature analyse etc

HV diff-probe, i now use it more as the normal probes

And to my surprise a Siglent SHS-1062 scope-meter. Not only for the isolated inputs and it being portable but it has logging capability on the screen and the one thing I now use often is the scope logging. Something I did not even bother to test at first. In that mode it is a logging Vac+dc meter that can sample at very high speed but plot slow. That turned out to be a very handy function. It "slowly" builds the trace but I found out it does not miss short events. I think it just samples continue and fills its memory before plotting the next point of the trace based on the peak or average for that time periode. Handy for fast, short signals that come by only now and then. (slow like in once in every 10 seconds or so, not hours)

I use some gear I designed and build myself, most used is a IC tester: http://www.pa4tim.nl/?p=5780
And a n Inductor Saturation tester : http://www.pa4tim.nl/?p=1859
And not really for measuring but handy for repair, a transformer winder: http://www.pa4tim.nl/?p=5731

http://www.pa4tim.nl/?p=5339 for those who do not want to spend 800 euro for de iprober. This is a bit like the HP547.

[nctnico]

I second the suggestion for a network analyser. Especially one which starts at 10Hz or so and has 1M Ohm input impedance as well. A network analyser is also very usefull as an LCR meter (albeit less accurate).

[PA4TIM]

I second the suggestion for a network analyser. Especially one which starts at 10Hz or so and has 1M Ohm input impedance as well. A network analyser is also very usefull as an LCR meter (albeit less accurate).

+1, if I work on RF equipment.

I have never seen a network analyser with a 1 meg input. (that is, if you mean vector and scalar models, I do not know about impedance meters)

[nctnico]

I second the suggestion for a network analyser. Especially one which starts at 10Hz or so and has 1M Ohm input impedance as well. A network analyser is also very usefull as an LCR meter (albeit less accurate).

+1, if I work on RF equipment.

I have never seen a network analyser with a 1 meg input. (that is, if you mean vector and scalar models, I do not know about impedance meters)

I have an Anritsu MS4630B network analyser (which can show phase information as well so I guess it qualifies as a vector network analyser). It's range is 10Hz to 300MHz and the inputs can be switched between 1M Ohm and 50 Ohm.

[nfmax]

Agilent N2786A scope probe holder. They are outrageously expensive new, but I came across a second-hand one that was merely very expensive. It looks too simple to work, but a combination of holes of exactly the right size (for HPAK probes), enough weight to tame the probe cable, and feet with a tacky finish to stop it sliding about, mean it does the job on those occasions when you just run out of hands.

[PA4TIM]

Nico: nice piece of kit. The low frequencies and 1M input make it nice for component testing. Anritsu calls it a VNA and it does phase, so if it look like a VNA, smells like a VNA..... 

nFmax. I have never used a probeholder but thought about it. Often I need to adjust things on the scope while trying to keep the probe in place and not short 2 pins (smd work) Are they really handy ?  I'm afraid that if I touch the cable or so the probe moves and make a short. They look like it is not difficult to make your own.

[Vgkid]

A milliohm meter. My 3205B has proven itself to be rather entertaining.
 Currently testing some rotary switches...

[R005T3r]

a good Faston crimping tool.

I thought I could simply crimp + solder faston connectors, but I was wrong, because I'm using them quite often nowadays and it's not really worth the pain, especially in particular spaces...  The only problem is that crimpers don't come cheap...

[nfmax]

A milliohm meter. My 3205B has proven itself to be rather entertaining.
 Currently testing some rotary switches...

Agreed! I have an Agilent U3606A, which is a pretty nondescript DMM, except that it has real milliohm ranges as a side benefit of the built PSU. Very handy at times, despite the noisy fan.

[nfmax]

Nico: nice piece of kit. The low frequencies and 1M input make it nice for component testing. Anritsu calls it a VNA and it does phase, so if it look like a VNA, smells like a VNA..... 

nFmax. I have never used a probeholder but thought about it. Often I need to adjust things on the scope while trying to keep the probe in place and not short 2 pins (smd work) Are they really handy ?  I'm afraid that if I touch the cable or so the probe moves and make a short. They look like it is not difficult to make your own.

You do have to be careful, but in my experience the UUT is more likely to move than the probe holder. I agree it probably wouldn't be difficult to make one, but you have to get the details exactly right. Easier to do once you have one to play with.

[mc172]

I second the suggestion for a network analyser. Especially one which starts at 10Hz or so and has 1M Ohm input impedance as well. A network analyser is also very usefull as an LCR meter (albeit less accurate).

+1, if I work on RF equipment.

I have never seen a network analyser with a 1 meg input. (that is, if you mean vector and scalar models, I do not know about impedance meters)

I have an Anritsu MS4630B network analyser (which can show phase information as well so I guess it qualifies as a vector network analyser). It's range is 10Hz to 300MHz and the inputs can be switched between 1M Ohm and 50 Ohm.

Your network analyser is really two instruments in one - a half-baked RF network analyser and an AF network analyser. The 1 Meg ports are probably only really useful for audio gear up to a few hundred kHz. Operation down to audio frequency such as the mental 10 Hz is also not really very useful for anything you will be measuring using the ports at 50 Ohms . Why would you ever want, or more importantly need some RF gear to work from 10 Hz to 300 MHz? Even 30 Hz to 30 MHz is bonkers.

A 300 MHz upper frequency limit is pretty low for a network analyser. Most go to 3 GHz and won't have 1 Meg impedance options, mostly because the impedance of the connectors is important when you leave 300 MHz behind. Rohde & Shwarz don't even make their instruments in 75 Ohm flavour, let alone 1 Meg.

[Vgkid]

Agreed! I have an Agilent U3606A, which is a pretty nondescript DMM, except that it has real milliohm ranges as a side benefit of the built PSU. Very handy at times, despite the noisy fan.

That is a pretty interesting piece of gear. To bad the milliohms accuracy isn't that great, but it is using a constant dc current. Which is expected.

[bson]

I second the suggestion for a network analyser. Especially one which starts at 10Hz or so and has 1M Ohm input impedance as well. A network analyser is also very usefull as an LCR meter (albeit less accurate).

The old HP 3577A is one of my most used instruments... and I don't really ever do anything RF.  But being able to measure frequency and phase response, and hence group delay of acquisition and reconstruction filters is golden.  And those are often well below the bandwidth of modern RF instruments.  1Mohm works very well for this; no need for a 50ohm transmission line for a DC-1kHz acquisition filter, in fact it's undesirable.

[bson]

Your network analyser is really two instruments in one - a half-baked RF network analyser and an AF network analyser. The 1 Meg ports are probably only really useful for audio gear up to a few hundred kHz. Operation down to audio frequency such as the mental 10 Hz is also not really very useful for anything you will be measuring using the ports at 50 Ohms . Why would you ever want, or more importantly need some RF gear to work from 10 Hz to 300 MHz? Even 30 Hz to 30 MHz is bonkers.

The phrase you're searching for is "IF and baseband", which is the purpose of these instruments, and exactly how we use them.

[all_repair]

Had them a while now 'cause everything now is SMD.

Smart Tweezers.
http://www.smarttweezers.com/st5s/

Mine are older ST3, powered with LR44's.
Easily in my top 5 pieces of gear as I use them on nearly all fault finding/component testing, TH and SMD.
ESR tests too.

Indispensable. 

Because of your post, I was choosing between LCR Pro 1 and ST5S, then found MS8910A and bought it.  It is an improved version of MS8910.