{"id":50658,"date":"2024-08-14T11:20:52","date_gmt":"2024-08-14T09:20:52","guid":{"rendered":"https:\/\/www.nordtec.se\/uncategorized\/thermocouple-wire\/"},"modified":"2026-04-28T14:11:51","modified_gmt":"2026-04-28T12:11:51","slug":"thermocouple-wire","status":"publish","type":"post","link":"https:\/\/www.nordtec.se\/en\/tips-tricks-en\/thermocouple-wire\/","title":{"rendered":"Thermocouple wire"},"content":{"rendered":"\n
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Published 2024-08-14<\/p>\n\n\n\n

Thermocouple wire<\/p>\n<\/div><\/div>\n\n\n

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\"Thermocouple<\/a><\/figure>\n<\/div>\n\n\n

Practical tips on thermocouple wire – make your own temperature sensor<\/h2>\n\n\n\n

The measurement principle<\/strong><\/p>\n\n\n\n

Thermocouple wire measurement is based on a simple principle – namely that temperature differences in electrical circuits of 2 different metals lead to the generation of an electrical voltage. The greater the temperature difference between the reference point (the connection point on the instrument) and the measurement point (the wire or sensor end), the higher the voltage. A thermocouple therefore consists of 2 metal wires with different properties. Therefore, it is also important to allow the instrument to adjust to the ambient temperature before you start measuring, in order to avoid incorrect measurement results. <\/p>\n\n\n\n

A flexible approach<\/strong><\/p>\n\n\n\n

The advantage of measuring temperature with thermocouple wire is that the temperature range and the distance between the instrument and the measurement point can be precisely adapted to the measurement task. The distance to the measurement point can be up to 100 meters if proximity to electric fields is avoided. The temperature at the measuring point can also be up to over 1 200 \u00b0C. <\/p>\n\n\n\n

The simplicity<\/strong><\/p>\n\n\n\n

As described later in this article, it is easy to make your own so-called wire sensors from thermocouple wire. Choose a thermocouple wire with the right insulation depending on the ambient temperature (PVC-insulated wire can withstand up to 105\u00b0C and fiberglass-insulated wire can withstand up to 480\u00b0C). <\/p>\n\n\n\n

Cut the wire to the desired length – strip both ends – twist the wires together at one end and connect a thermocouple connector at the other – connect the connector to the instrument – Ready for measurement!<\/p>\n\n\n\n

Applying the wire sensor<\/strong><\/p>\n\n\n\n

The wire sensors can measure temperature in air, liquids and on surfaces. For air and liquid measurements, all that is required is to place the wire sensor measurement point in the desired location. When it comes to measuring on surfaces, there are some tricks. For example, when measuring on pipes, the measuring point can be applied using tape or a hose clamp. When measuring on open surfaces, the measuring point can be glued, taped or clamped. It can also be soldered or spot welded. <\/p>\n\n\n\n

There are different types of thermocouple sensors. In short, type T has a narrower temperature range and higher accuracy (e.g. for food control) while type K has a much wider temperature range. These are also the 2 most common types that our customers order from us. See the table below for more variants and more detailed info. <\/p>\n\n\n\n

Measurement points<\/strong><\/p>\n\n\n\n

If possible, welding the wires at the measuring point gives the best strength. It is also possible to solder or twist the wires (or both). <\/p>\n\n\n\n

If you twist<\/strong><\/p>\n\n\n\n

Twist the conductors together at the far end (approx. 5-10 mm), preferably with the aid of a pair of pliers to ensure proper galvanic contact. Otherwise, oxidation can lead to gaps or breaks in the long term. <\/p>\n\n\n\n

Polarity<\/strong><\/p>\n\n\n\n

Almost all thermocouple wire sold in Sweden is according to the IEC 60584 standard, which means that the white conductor is always minus and that the color of the thermocouple contacts is green for type K and brown for type T. The contacts are marked with plus and minus.<\/p>\n\n\n\n

Tip to check that you have connected the wire sensor correctly: warm the wire end (measuring point) with your hand. If the temperature value increases in the instrument, the wires are the right way round (doesn’t work as well if you come in from the cold and have very cold hands of course…). <\/p>\n\n\n\n

Interruption of the sensor wire<\/strong><\/p>\n\n\n\n

If the sensor wire has broken, come loose or is loose in the connection to the instrument, the instrument display will normally show only dashes (- – -).<\/p>\n\n\n\n

Short circuit between the wires<\/strong><\/p>\n\n\n\n

If the insulation is damaged and the conductors are short-circuited, a measurement point is created at that location. The instrument will then display the temperature at the short-circuit point instead of at the measuring point (wire end). <\/p>\n\n\n\n

Measurement error<\/strong><\/p>\n\n\n\n

Earth currents and electric fields can lead to inaccurate readings. A rule of thumb is that the thermocouple wire should not be drawn closer than half a meter from a power cable. This is more sensitive the longer the wire you use. You can also test practically by moving the wire closer and further away from a possible electric field, if the instrument shows fluttering values, it is likely that a disturbance is taking place. <\/p>\n\n\n\n

If you need to extend a thermocouple wire, it is important that you use exactly the same type of wire and do not mix in other materials. A female TE connector is fitted at one end of the extension wire and a male connector at the other end. Better still, change the entire wire sensor to one of the correct length, all the way from the measuring point to the instrument. <\/p>\n\n\n\n

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Search thermocouple wire on roll<\/span><\/a><\/div>\n<\/div><\/div>\n\n\n\n

Technical data according to international standard IEC 60584-3<\/p>\n\n\n\n\n\n\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t
TE-typ<\/strong><\/td>F\u00e4rg<\/strong><\/td>Temperatur­omr\u00e5de<\/strong><\/td>Egenskaper<\/strong><\/td>\n<\/tr>\n
K<\/td>Gr\u00f6n\/Vit<\/td>-200 … 1 260 C\u00b0<\/td>Brett temperaturomr\u00e5de. Kan anv\u00e4ndas i oxiderande milj\u00f6er.<\/td>\n<\/tr>\n
T<\/td>Brun\/Vit<\/td>-200 … 370 C\u00b0<\/td>Sn\u00e4vare temperaturomr\u00e5de och h\u00f6gre noggrannhet.<\/td>\n<\/tr>\n
J<\/td>Svart\/Vit<\/td>-200 … 760 C\u00b0<\/td>Passar inte f\u00f6r oxiderande milj\u00f6er.<\/td>\n<\/tr>\n
E<\/td>Lila\/Vit<\/td>-200 … 900 C\u00b0<\/td>Kan anv\u00e4ndas i oxiderande milj\u00f6er.<\/td>\n<\/tr>\n
N<\/td>Rosa\/Vit<\/td>-200 … 1 300 C\u00b0<\/td>Som typ K, men b\u00e4ttre \u00f6ver 200 \u00b0C.<\/td>\n<\/tr>\n
S, R<\/td>Orange\/Vit<\/td>0 … 1 480 C\u00b0<\/td>Keramiskt skyddsr\u00f6r i alla milj\u00f6er.<\/td>\n<\/tr>\n
B<\/td>Gr\u00e5\/Vit<\/td>0 … 1 700 C\u00b0<\/td>Keramiskt skyddsr\u00f6r i alla milj\u00f6er.<\/td>\n<\/tr>\n
C<\/td>R\u00f6d\/Vit<\/td>425 … 2 315 C\u00b0<\/td>Keramiskt skyddsr\u00f6r i alla milj\u00f6er. Fr\u00e4mst f\u00f6r vakuum.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n\n\n\n