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WICKON Q12: 12-channel specifications and thermocouple placement
The Q12 and Q24 are two channel-count versions of the same platform. Accuracy, resolution, memory and software are the same; the only differences are how many thermocouples can be attached at once and the body size. So choosing between Q12 and Q24 is really a process question: how many points does this board need?
This page lists the Q12 specifications first, then covers placement, because whether you use all the channels depends on your placement plan, not the other way round.
1. Q12 specifications
| Item | Q12 | Q24 (for comparison) |
|---|---|---|
| Channels | 12 | 24 |
| Body size | 192 × 45 × 20 mm | 156 × 83 × 20 mm |
| Accuracy | ±0.5 °C (full range) | ±0.5 °C (full range) |
| Resolution | 0.01 °C | 0.01 °C |
| Measuring range | −200 to 1370 °C | −200 to 1370 °C |
| Max. internal operating temperature | 105 °C | 105 °C |
| Total memory | 4,000,000 points | 4,000,000 points |
| Sampling interval | 0.05 s to 86,400 s | 0.05 s to 86,400 s |
| Thermocouple type | K | K |
| Battery | Rechargeable lithium polymer | Rechargeable lithium polymer |
| Analysis software | Insight | Insight |
Note the difference in shape: the Q12 is long and narrow at 192 mm × 45 mm; the Q24 is 156 mm × 83 mm. Both are 20 mm thick. The width differs by almost double, so if your oven belt width is limited or your fixture opening is a long slot, the shape may decide the model before channel count does. Measure the usable oven entrance and belt width before ordering.
2. How many thermocouples, and where
There is no single right answer, but there is a logic to follow. The purpose of profiling is to show that every solder joint on the board falls within the process window, and temperature differences across the board come from differences in thermal mass and position. So placement should cover the extremes of both.
- High thermal mass: large connectors, heavy copper layers, large ground planes, near metal shields. These heat more slowly and represent the risk of insufficient temperature.
- Low thermal mass: small passives, thin board edges. These heat faster and represent the risk of overheating.
- Board position extremes: leading edge, trailing edge, left and right sides, center. Uneven airflow and heating in the oven show up here.
- Components to protect: parts with little temperature margin (such as some connectors, electrolytic capacitors and moisture-sensitive devices) should each get their own thermocouple regardless of thermal mass.
- On the carrier or fixture: if a pallet or fixture goes through the oven, its thermal mass affects the board; place at least one thermocouple on the fixture as a reference.
Taking one or two points from each category, most single-board profiles need 6 to 12 thermocouples, which is why 12-channel models cover a wide range of uses. 24 channels are usually needed when profiling several boards in one pass (panels or multiple carriers), when a large board needs denser position sampling, or when oven uniformity verification and product profiling are done together.
3. Thermocouple attachment directly affects readings
At the same point with the same instrument, different attachment methods give different profiles. This is a common source of profiling error.
- The junction must touch the point being measured: a thermocouple measures the temperature of its junction. If it is not firmly attached, it reads a mix of nearby air and radiation.
- Attachment materials have thermal mass: high-temperature solder, thermal adhesive and aluminum tape each have different thermal mass and conductivity, changing how that point heats. Use one attachment method within a measurement set, or points cannot be compared.
- Route the wire away from direct heat: if the wire near the junction is exposed to hot air or radiation, heat conducts along the wire to the junction and raises the reading. In practice, run the wire along the board surface for a short distance before leading it away.
- Measure the same way every time: for trend comparison or SPC, fix the placement and attachment method in your work instruction; otherwise you cannot tell whether the process or the measurement changed.
4. If not all channels are used
There is no need to use every channel. Leave unused channels empty and the software skips them. A common practice is to reserve one or two channels as oven reference points (measuring oven air or the fixture, not the product), giving each run a common baseline for comparing profiles across batches.
5. Shared with the Q24
Apart from channel count and body size, the Q12 and Q24 share the same platform: the same accuracy and resolution, the same 4-million-point memory, the same K-type thermocouples, the same Insight software (including PWI judgment, SPC calculation and ROS rapid oven setup), and the same thermal barrier technology and accessories. For the full platform, software and thermal barrier selection, see the WICKON Q24 specification page.
FAQ
Are 12 channels enough? Most single-board profiles use 6 to 12 points, so 12 channels cover them. You may need more when profiling several boards or carriers in one pass, when a large board needs denser sampling, or when doing oven uniformity verification and product profiling together. If you profile single boards and do not plan to profile several at once, 12 channels is usually suitable.
Do the Q12 and Q24 give different results? No. Accuracy, resolution, memory, sampling interval and thermocouple type are identical; only channel count and body size differ. With the same placement and attachment, both should record the same profile.
Will the longer body fit through the oven? The Q12 is 192 × 45 × 20 mm and the Q24 is 156 × 83 × 20 mm; both are the same thickness but differ in proportions. Whether it fits depends on oven entrance height, belt width and the overall size of the thermal barrier with the logger inside, not the logger alone. Send us your oven entrance and belt dimensions before ordering so the thermal barrier can be confirmed.
Which thermocouple wire gauge? Wire gauge affects thermal mass and response: fine wire responds quickly and disturbs small components less but is more fragile; heavier wire is durable but has more thermal mass and may lag during fast ramps. SMT reflow profiling generally favors fine wire.
Can I still buy thermocouples and consumables for an older unit? Thermocouples, thermal barrier insulation and data cables can be bought separately. If you already have a Wickon unit and only need consumables, ask us; you do not need to replace the whole system.
Standards referenced
Please refer to the current versions published by each organization.
- IPC J-STD-001, Requirements for Soldered Electrical and Electronic Assemblies — Global Electronics Association (formerly IPC)
- IPC-A-610, Acceptability of Electronic Assemblies
- ISO 9001:2026, Quality management systems – Requirements, Ed. 6 — International Organization for Standardization (ISO)
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Related: WICKON SMT reflow profilers · WICKON Q24 reflow profiler · WICKON thermal barrier temperature ratings · KIC reflow profilers
From: JIAHON Engineering
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