Oh dear: shouldn't have touched that 'calibration' screw...

[lorriman]

Like an idiot I changed a calibration screw on my Circuit Specialist 1A solder station without making a note of its original position. In fact I am an idiot. I'm now convinced that it is underheating. Even at 800F it seems to be slow to melt.

However maybe it's just me and it's actually quite close to the right temp; I just don't know. I don't have enough experience to tell. In the meantime I'm a bit OCD about these things: having decently calibrated equipment (I have lots of measurements tools and a decent magnifier) really removes a lot of thrashing around in the dark. I would like to follow soldering advice that suggests a certain temp to avoid component damage. But right now I can't.

Emailing Circuit Specialists they say that 'it can't be calibrated'. Oh great!

Any suggestions from an ingenious mind as to how I might go about this?

So far I've tried an IR thermometer but their circle of temperature detection is way too large and they are in any case very inaccurate.

Is there in fact a standard method for calibrating these things? Would I be better off just getting another station; in view of the cost of calibration?

[simon7000]

All you need is patience and a piece of plumbers 40/60 solder. Wrap a piece around the tip and set the iron for 230 degrees. If you are calibrated too low it won't melt!

if you don't have 40/60 then try a 95/x/x that should melt around 224 C!

[5th element]

The thermocouple that came with my multimeter is good up to 250 degrees C and with high accuracy too. You could easily use something like this to calibrate the unit at a lower temperature.

[lorriman]

Originally Posted by simon7000

All you need is patience and a piece of plumbers 40/60 solder. Wrap a piece around the tip and set the iron for 230 degrees. If you are calibrated too low it won't melt!

if you don't have 40/60 then try a 95/x/x that should melt around 224 C!

Thanks for the help. Is this an established technique? Obviously I query it simply because 230C isn't near the melting temp of 40/60.

[lorriman]

Originally Posted by 5th element

The thermocouple that came with my multimeter is good up to 250 degrees C and with high accuracy too. You could easily use something like this to calibrate the unit at a lower temperature.

I tried it with mine and while at one point I got a steady temp that was in the region that I had set the station (about 40C less) on attempting to repeat I got wildly different results: much much less.

So I'm wondering at a better or standard method for doing this.

[c2cthomas]

Perhaps something such as this???

I can't vouch for this unit as I have never used it YMMV

Digital Thermometer K-Type Metal Thermocouples 4 Probe Sensor 1300°C 2372°F | eBay

[simon7000]

Originally Posted by lorriman

Thanks for the help. Is this an established technique? Obviously I query it simply because 230C isn't near the melting temp of 40/60.

40/60 not 60/40! It is used for proof of performance. Of course there is also a stopwatch on the power on to melt time. When the tip has stabilized in temperature it is supposed to melt an .100" wire in 3 seconds.

[5th element]

The thermocouple that came with my meter isn't an IR device and is accurate. The only problem with it is that it's prone to inaccuracy if whatever it is measuring is charged to any kind of electrical potential, or if the target has high speed switching going on near it.

If you've got a standard metal thermocouple then what I do is get the target up to temperature, attach the thermo couple, then turn whatever it is off. If the target is interfering with the measurement in some way then this usually does a good job of removing it from the picture.

What simon is suggesting is also a valid way of doing this. Eutectic solder melts at only one temperature. If you were to wrap a ring of some standard alloy solder with a known melting point around the tip of the iron, then you could set the iron to say 180 degrees. 63/37 standard lead solder melts at exactly 183 degrees C. If you set the calibration screw so that the iron is running cold, then if you set it to 180 and then slowly ramp up the screw till the solder melts, then you know your 180 setting is @ roughly 180 degrees.

[lorriman]

@simon aha, understood

@5th Thanks for the thermocouple advice.

My station doesn't go lower than 200C horribly and I assumed that would be true for others. Might have to try finding some of that plumbers solder.

[lorriman]

Originally Posted by aptquark

get one of those laser heat gun sensors...they're cheap now. Point it at the tip, and read the temp.

You mean the IR thermometers. They don't work for this as they are very inaccurate and also have to large a detection circle (the laser is purely for guidance as to the center of the circle).

I tried.