AT THE BENCH
The useful part, first.
- Compare the same joint, tip geometry and starting temperature.
- Separate displayed temperature from independently measured tip temperature.
- A larger contact surface can help more than a higher setpoint.
Published sample / ALIENTEK T90B
A setpoint is only half the story.
Gough Lui's external Weller WCU readings at three settings. These are accuracy readings, not a thermal-recovery curve.
The joint is the load
An iron can reach its setpoint quickly in air and still struggle with a connector ground tab. The board, lead and solder draw heat from the tip. The useful questions are how far the working temperature falls, how long it takes to recover, and whether the joint wets before nearby materials spend too long being heated. A power rating describes a limit of the system; it does not answer those questions on its own.
Thermal capacity and recovery are related but different. A heavier tip stores more heat. A responsive heater replaces energy lost to the joint. Contact area controls how effectively that energy crosses into the work. A fine conical tip on a large ground pad can therefore perform poorly even on an expensive station. Choose a geometry that makes stable contact without touching adjacent conductors.
A published example with useful limits
Gough Lui’s ALIENTEK T90B review is valuable because it uses an external Weller WCU temperature tester and records temperature behaviour with a DAS240 logger. His reviewed sample measured 330.1°C at a 350°C setting, 416°C at 450°C, and 186.1°C at 200°C. These are results for that sample, tip and method, not a correction table for every T90B and not measurements made by ReworkKit.
The difference varies across the range. A single offset established at one temperature cannot automatically correct the rest. Gough also explains that the thermocouple adds a thermal load and has its own response delay. That qualification matters: a curve is only useful when the reader knows what the sensor is actually recording.
| T90B setting | Gough’s measured value | Interpretation |
|---|---|---|
| 200°C | 186.1°C | One published sample and test setup |
| 350°C | 330.1°C | Display and external measurement differ |
| 450°C | 416°C | Difference is not a constant offset |
Make the comparison repeatable
Prepare identical sacrificial boards or copper coupons. Record copper area, board thickness, ambient conditions, solder alloy, flux, tip shape and tip condition. Start each run from the same stabilised temperature. Use the same contact position and pressure, and allow the fixture to return to its starting condition between runs. Keep a photograph of the contact geometry beside the results.
Record the minimum measured temperature, recovery time to a defined band, time to acceptable wetting, and any failure to complete the joint. Repeat the test. If the probe changes contact during a run, mark it as invalid. A station display alone is insufficient: the internal sensor can be some distance from the working surface. A filmed joint is useful context, but retain the underlying time series when a logger is available.
Buy for the work you repeat
For fine component work, look for a controllable small tip and a comfortable handle. For ground planes, connectors and heavy wire, first test a broader tip; then consider more heater capacity or board preheating if the task still stalls. Increasing the setpoint can shorten one task while increasing damage risk on the next. SDG’s Metcal and JBC comparison is a useful lead for heavy thermal loads, although the measurements are primarily in the companion video and were not fully audited in our source research.
A practical buying note should end with a task boundary: which joints the tested combination completed, which required another tip, and which needed a different heating approach. “Fast heat-up” is a separate observation. It should never stand in for performance on a board.
THE RECORD
Sources & limitations
Research was gathered on 21 September 2026. These links were not freshly reverified for this edition. A test result is specific to its sample, setup and stated conditions.
- Gough Lui: ALIENTEK T90B review
Original webpage measurements read in the 21 September 2026 research. Review sample supplied by ALIENTEK.
- SDG: Metcal GT120 vs JBC thermal capacity
Video companion page. Treat the test as a research lead; the full video measurements were not independently transcribed.