The key difference is the insulation. PTFE (TTK) is rated to 260 °C and is used for standard reflow oven profiles; glass fiber (GGK) is rated to 480 °C and is used for wave soldering or processes where you need to track high peak temperatures. The wrong insulation can give measurement errors or even char the insulation layer.
Conductor diameter (-30 vs -36) affects thermal response and how easy the wire is to weld. The fine -36 wire (0.127 mm) responds quickly and is used when welded onto a PCB for precise tracking; the thicker -30 wire (0.255 mm) is mechanically stronger and is used for fixed measuring points in the oven that are mounted and removed repeatedly.
Specifications of the 4 models
| Model | Insulation | Range | Conductor diameter | Main use |
|---|---|---|---|---|
| TTK-30 | PTFE | 0 – 260 °C | 2 × 0.255 mm | Fixed oven measuring points, general SMT temperature monitoring |
| TTK-36 | PTFE | 0 – 260 °C | 2 × 0.127 mm | Precise measurement welded on the PCB, reflow profile sampling |
| GGK-30 | Glass fiber | 0 – 480 °C | 2 × 0.255 mm | Wave soldering, high-temperature ovens, oven chamber temperature |
| GGK-36 | Glass fiber | 0 – 480 °C | 2 × 0.127 mm | Precise profiles in high-temperature processes, wave soldering PCB measurement |
Conductors for all models: chromel (positive) / alumel (negative), type K thermocouple as defined in IEC 60584.
Thermocouple types: K, J, T, E, N and noble metal
Thermocouples are grouped by the two metals used, and each type has its own range and uses. Ranges below are the thermocouple-grade wire ranges published by OMEGA, not the coverage of the IEC 60584-1 tolerance classes.
| Type | Positive | Negative | Range (thermocouple-grade wire) | Characteristics and common uses |
|---|---|---|---|---|
| K | Nickel-chromium | Nickel-aluminium | −200 – 1250 °C | Common general-purpose type, wide range, durable |
| J | Iron | Constantan (copper-nickel) | 0 – 750 °C | Higher sensitivity; limited in high-temperature oxidizing environments |
| T | Copper | Constantan (copper-nickel) | −250 – 350 °C | Copper / constantan pair, often used for differential measurement |
| E | Nickel-chromium | Constantan (copper-nickel) | −200 – 900 °C | Large output signal, used for low-temperature and freezer measurement |
| N | Nicrosil | Nisil | −270 – 1300 °C | Good stability and oxidation resistance |
| S / R / B (noble metal) | Platinum-rhodium (S 10% Rh, R 13% Rh, B 30% Rh) | Platinum (B: platinum–6% rhodium) | S 0 – 1400 °C; R 0 – 1450 °C; B 0 – 1700 °C | High-temperature measurement (higher cost, lower sensitivity) |
Sources: ranges and wire materials from OMEGA (dwyeromega.com/en-gb/colorcodes); characteristics and uses from the Wikipedia “Thermocouple” article.
Common probe styles
- Bare wire, welded tip: the two wire ends are welded into a measuring junction that is attached to a PCB pad or the measured object.
- Screw type: the probe is screwed onto the surface or into a threaded hole, for fixed measuring points.
- Magnetic: held on metal surfaces by a magnet, for temporary measurement.
Order options
| Option | Includes | When to use |
|---|---|---|
| Wire + welded tip | Bare wire with welded junction | With your existing K plugs, or wired straight to instrument terminals |
| K plug + wire + welded tip | K-type plug to OMEGA dimensions + wire + welded tip | Plug straight into a profiler or instrument |
| K plug + wire + welded tip + holder | K plug plus holder fixture | Fixed oven chamber points, long-term measuring stations |
Choosing the length: in a reflow oven the distance from measuring point to instrument is usually about 100–150 cm, so choose 120–180 cm to leave some slack; if the wire has to route around the machine frame or oven body, choose a 200–300 cm version. Avoid extension connectors between the measuring point and the instrument, as they add measurement error.
Installation and use
- When welding the hot junction onto a PCB copper pad, keep the weld to 1–2 mm diameter. A larger weld adds thermal mass, and the measured peak reads slightly lower than the actual peak.
- Keep the cold end (K plug) at a stable temperature and check the plug direction before connecting. K plugs have asymmetric pins to prevent wrong insertion, but forcing a plug in can still reverse the reading.
- PTFE insulation resists chemicals (including flux vapour) but not abrasion. Glass fiber withstands high temperature but absorbs slightly more moisture than PTFE, so take care with long storage in humid conditions.
- Both are flexible wires; keep the bend radius at least 10 times the wire diameter.
TTK or GGK, AWG30 or AWG36
- TTK (PTFE): flexible, easy to route and fix; used for general reflow ovens, burn-in (low-temperature range) and long-term cleanroom environmental monitoring.
- GGK (glass fiber): stiffer, watch the bend radius at corners; used for high-temperature oven zones, burn-in tests and package reliability verification.
- AWG30 (suffix 30, thicker): resists bending and breakage; used for repeated plugging, fixed monitoring points and continuous monitoring of 72 h or more.
- AWG36 (suffix 36, finer): low thermal mass and fast response; used for reflow profile verification and fast sampling. The wire is fine, so avoid repeated bending.
Quick selection table
| Need | Model | Reason |
|---|---|---|
| Reflow profile verification, fast response | TTK36 | Fine wire, low thermal mass, follows changes closely |
| Fixed reflow monitoring point, durability | TTK30 | Thicker wire resists bending and repeated plugging |
| Burn-in high-temperature aging test | TTK-30 (PTFE, ≤ 260 °C); GGK only for special burn-in above 200 °C | Burn-in is generally about 125 °C, within PTFE’s range |
| Dynamic high-temperature oven analysis | GGK36 | Fine wire for fast response, plus high-temperature insulation |
| Long-term cleanroom monitoring (72 h+) | TTK30 | Durable, flexible, easy to route |
JIAHON-branded wire and calibration
- Brand on the wire: the JIAHON brand is marked on the wire, so each wire can be traced back to a responsible supplier.
- Calibration report: TTK-36 and GGK-36 wires were sent to a third-party calibration laboratory in January 2025; the report is available in the documents section of the Chinese page.
- K plug fixing: instead of a conventional clip, the K plug uses a multi-point pressure fixing for stable conductor contact under repeated plugging and high-temperature cycling.
- Automated argon welding: our own argon-shielded welding line reduces oxidation at the junction and gives a smaller weld for faster thermal response.
- OMEGA-brand thermocouple wire (TT-K-30, TT-K-36, GG-K-30 and others) is also available on request.
Common questions
Can PTFE (TTK) wire be used for burn-in? Burn-in is generally about 125 °C, within the 260 °C rating of PTFE; GGK is only needed for special burn-in above 200 °C.
Do your K plugs fit OMEGA-style K connectors? The K plug option follows OMEGA K-type plug dimensions, for direct connection to a profiler or instrument.
Trademarks: OMEGA and the model names TT-K / GG-K are trademarks or model names of their owner, used here only to identify connector dimensions and the wire models we can source. JIAHON is not the authorized distributor of OMEGA in Taiwan.
Request a quote
Send the model (TTK-30 / TTK-36 / GGK-30 / GGK-36), the order option, length, quantity and your oven or process temperature. Request a quote →