T12 clone vs Metcal SP200

[Tarloth]

Mine Hakko 888 lives at around 300-305C, 95% of the time, for leaded solder.

Even though the solder melts at under 200C, the temp sensor of the station is regulating the back of the tip, not the joint.

If you could make an iron with infinite power, sensor in the very point of the tip, and ridiculous accuracy using ESP, you would still need to set the temp higher than the melting temp of the solder. Else you would have an iron that could maybe melt its way through a blob of solder without reflowing the entire blob.

EXACTLY!!!! A solder station set to 300 c degrees it's OK for most of the task and not implies that the component it's at that temperature because the thermal transference it's not infinite nor instantaneous. At this point it's irrelevant if the exact temperature in the heat element it's 285 or 315 degrees, the only that matters it's that component will be perfectly solder at least time posible to avoid that the core exceed the upper limit temperature.

[Shock]

According to IPC J-STD-001E and IPC J-STD-001F +-10% temp accuracy would make your station start to fall outside the standard above 100C, +-5% and it would fall outside the standard at 200C.

I don't have IPC J-STD-001G to check but in IPC J-STD-001F they changed from tip accuracy to the station being able to "maintain control" at the selected or required temperature. This doesn't mean that temp accuracy is excluded it's just encompassed in with recovery speed.

Even your latest example 300C +-5% 285C or 315C is outside IPC J-STD-001F as well. It's +-10C or +-18°F.

[Tarloth]

You still do not understand my statement! From the J-STD-001F

"A-2 BENCHTOP AND HAND SOLDERING SYSTEMS"

Selection criteria of benchtop and hand soldering systems include:

a. Soldering systems are selected for their capacity to heat the connection area rapidly and maintain sufficient soldering temperature
range at the connection throughout the soldering operation

b. Equipment should be able to maintain control within ±10°C [+18°F] of the selected or required temperature during multiple point-to-points or thermal mass on demand soldering operations to verify temperature stability.
c. Temperature stability-degradation to peak [set] recovery temperature – should be periodically checked to demonstrate soldering device can provide temperature control limits defined in Section (b) for multiple load, point-to-points soldering [for example; soldering of a multi-leaded component (s)] or depending on thermal mass demand soldering.
Note: Frequency of verification of temperature stability should be dictated by objective evidence of compliance to Section
(b).
d. Temperature stability-degradation to recovery overshoot - should be checked using point to point or on thermal mass demand soldering and shall not exceed the limits defined in section (b).

The range of control mentioned it's for stability of the temperature overshoot BETWEEN point to point or high thermal mass loads, not during the soldering process itself in determinate point. First point explain exactly this by specifying that the solder system need to maintain "sufficient soldering temperature throughout the soldering operation".

The did not talk about any range during the solder of some point, only specify which range need to maintain between different soldering points when the tip recover at air and applies to the next point. IPC talks about stability across different points and that be accomplish with all good brand solder stations, even the old ones with a rudimentary but reliable analog control of the tip. My principal concern with clones if this point it's or not assured, with good and proved brands I haven't any concern.

NEVER IPC did talk about the accuracy of the temperature that the solder station was set. They did said "selected or required temperature" and not specify any range within the temperature that say at the "screen" and actually have at the tip.

As I mention in previous posts it's irrelevant if you set the temperature at 330 degrees and the station actually stay at 300 or 290 in air and drops 260 during soldering. The norm says that the important it's that when recover from soldering at a point to soldering to the next point it need  will adjust it between +-10 degrees from previous state to garantieses  the stability of all the points soldered in the process.

Off course you need to calibrate with an external certified device (with removable sensor or thermal image) that the showed temperature at display be most near possible to the actual temperature at the tip but a stable difference between the seted temperature and real temperature will not invalide the norm accomplish.

When sensor (TC) at thermal element in the point getting old the temperature measured shift no matter of which advanced method hast the station to measure it or how many bits use to measured it.  When the iron tip it's new off course that the measured value it's according the desired value within a small range, when it get old not. It's a physic fact about TC and you need to recalibrate they frequently even with the most accurate sensor is used.

While it's a fact that you need to re calibrate the measured value against the aged TC or change the tip periodically if you prefer to be confident in the internal measure system of the station, a gap between the actual temperature and the supposed temperature not affect the final result. Metcal it's based in a physics phenom of material not in a TC , but still changes that did originated in the thermal cycling  in the material alter the final temperature (less than in a TC) , but consistently maintain the limits at max temperature or overshoot. This it's the relevant point in all stations, that they assure that the temperature never will be highest that a max set. 

All good solder stations garantieses the overshoot and range of stability in air off the PCB,  but never garantieses that the absolute temperature set would be the "exactly the same" between different tips or through their aging process and that it's ok with the norm. Also, if you take in consideration that the temperature considerably drops at soldering process, it's irrelevant if the set point differ with the actual value at tip point meanwhile it be stable and capable of do the job.

The IPC norm simply specify this, you need to guarantee the stability of soldering temperature at air in similar points, but you able to set ANY temperature that you considere necessary to do the job. In the other norms they specify that the core temperature at component never be highest that specified to a reflow process but even that, they still not determines which exactly will be the set temperature at solder station to accomplish with a correct melted and soldering process. If you prefer  set you station to 300 degrees it's correct and if somebody set it to 330 because the real temperature at the tip it's 300 is still ok. Good solder stations garantieses stability, soldering temperature it's a matter of user necessities and it's irrelevant the accuracy that you have to measured it, only matters good stability and good soldering process. And this it's according with the IPC norm.

[Shock]

If you have a +-10% temp accuracy at 250, 300, 350C how are you supposed to maintain control at those temperatures then to +-10C according to IPC IPC J-STD-001F?

In the IPC J-STD-001E it was tip temperature at idle +-5C, as I mentioned many other standards are +-6C or lower tip temperature. Do you think IPC just raised it to +-10C and to "maintain control" for fun? They probably wanted to single out stations with poor power delivery, thermal recovery and overshoot.

If you take your Hakko FX888D and it had +-10% temp swing at idle across it's operational range it would be faulty, not according to IPC but according to Hakko (spec is +-1C at idle between 200-480C). Notice it doesn't say +-48C at 480C. Which would mean one operator could be soldering at 432C and another at 538C.

Like I said, if you're soldering to IPC standards I'm fairly sure +/-10% is a fail.

[floobydust]

Found T12 tip/heater disassembly pics.
It looks like it's mostly about the thermal resistance of the ceramic filler and insulator, as well as tip thermal mass.
Would have to compare with JBC's technology for getting the heat from the NiCr to the tip.

[Tarloth]

If you have a +-10% temp accuracy at 250, 300, 350C how are you supposed to maintain control at those temperatures then to +-10C according to IPC IPC J-STD-001F?

Because I can have a station that shows in the screen (for example) 320 c degrees and control it perfectly in the range +- 1 C degree (very good stability!) but actually have 290 degrees at tip (also +-1 degree) !!!!!!

That it's I trying to say you!!! Stability it's different of Accuracy!!!

You are mixing two different concepts.

One is the stability to keep any temperature at soldering tip and the guarantees repetitive behavior point to point and the other totally different concept it's the accuracy to measure THAT temperature. If your thermometer it's wrong for 20 degrees you still have a very stable control, works inside the parameters of IPC norm but you have not and accurate measurement of the actual temperature.

Again, it's irrelevant at which real temperature are your iron tip (between some reasonable values) meanwhile you can keep it stable.

PLEASE read the IPC standard!!!! They never told about ACCURACY told about STABILITY. You can select any temperature that you need for do the job, but you need to keep it stable.

And yes, I have the 888d with 11 different original tips (and three more that are counterfeit) all of them works very stable, but I read slightly different temperatures with an external thermometer even with the central set to the same temperature. If I use old original tips from the 936 station, the stability continues very (very) good but the actual tip temperature differs more with the set temperature.

I have a FX951 too, I notice better stability between the original 4 tips, but I not measure the same tip temperature that I set in the station. If I compare with a counterfeit tip, the stability it's about the same but the temperature difference it's highest than original tips. By the way, in all counterfeit's the thermal mass it's awfull compared with the originals. I measure the tip temperature with a Hakko FG100 borrowed from a friend (forever) and compared with my Fakkko FG100 that differs only a couple of tenths of degree of the original one.

In all cases I can asure a stability better than +/- 5 degrees as is stated by the norm.

[Shock]

When people are talking about the temperature accuracy of a station they aren't talking about how accurate someones tip thermometer is.

Just to remind you, I was discussing the temperature accuracy across the range of Metcal 600 series tips. i.e. differences in geometry, tolerances and measured temperature variances from expected operational temperature, measured at idle.

Are you now saying it's ok on a new Hakko FX-888D station (factory calibrated default tip) to measure the tip temperature within +-10% temp accuracy (across 200-480C) while the tip has +-1C temp stability (at idle temp as per manual)?

[Tarloth]

Just to remind you, I was discussing the temperature accuracy across the range of Metcal 600 series tips. i.e. differences in geometry, tolerances and measured temperature variances from expected operational temperature, measured at idle.

Yes, off course, for exactly that point I argue that the better of Metcal is his stability and the accuracy it's irrelevant. If your tip it's displaced 20 degrees less than the max temperature of the serie it's irrelevant from the point of view of standards because they are stable by design.

Are you now saying it's ok on a new Hakko FX-888D station (factory calibrated default tip) to measure the tip temperature within +-10% temp accuracy (across 200-480C) while the tip has +-1C temp stability (at idle temp as per manual)?

No, isn't OK if the station and tip are brand new, but would be OK if you use a tip 900 or counterfeit or different geometry (different thermal mass) or the Platinum resistor at calefactor it's aged.  And this point not affect the performance at all meanwhile the station will continue an stable operation. You can calibrate the station or not to adjust the difference, it's irrelevant for the quality of soldering process. If the solder it's correctly melted and the temperature is stable the process it's ok.

For example, from Hakko page (http://www.hakko.com/english/maintenance/topic_ondo_2.html)

When using the 900M-T-B tip with the set temperature of 350ºC, if the tip is changed to the 900M-T-I or 900M-T-K tip

If changing to the 900M-T-I, the displayed temperature is approx. 10ºC lower.
If changing to the 900M-T-K, the displayed temperature is approx. 30ºC higher.

And this stations comply with IPC standards since ever!

And if you take attention to this (I use 888d because you did talk about it, but all serious stations brands have published this graphs for each stations model with more o less gap)



Please see that setting at 350 degrees, with a very good stability control, temperature drops 70 degrees when touch the PCB. I ask you again, it's relevant if the initial temperature was 350,340 or 360 if it drops 70 degrees when soldering? IPC specify this when says "sufficient soldering temperature", not an absolute value, just the temperature that works but stable.

[Shock]

Are you now saying it's ok on a new Hakko FX-888D station (factory calibrated default tip) to measure the tip temperature within +-10% temp accuracy (across 200-480C) while the tip has +-1C temp stability (at idle temp as per manual)?

No, isn't OK if the station and tip are brand new...

I agree +-10% temp accuracy is not acceptable.

[Tarloth]

Please, quote the entire line of text that I publish. Have you read the text where Hakko explaining biggest differences than you considerer inacurate in perfectly acceptable solder stations that aprove all international standards? You told about norms that not say that you affirm that it say and definitely ignores anything that not confirm your position even with detailed explanations. It's ok, you can believe in anything that confort you.

People will continue to solder at temperature that works for them and they precisely work, and that it's correct within the IPC norm, even if hasn't any screen or dial that confirm the set temperature.

The only relevant it's the stability as IPC's norm claim. If you know the set temperature with any error it's a problem of your measure method, not of the process of soldering itself. With good stability the temperature it's correct even if you not know which is.

[Shock]

I've made my point already. I don't need to quote a page of text when it was a yes or no question. This is not an invitation to argue more with me because I'm not wasting anymore time on the subject.