ВР5 tungsten rhenium thermocouple wire
|Mark||Analogue||W. Nr.||Aisi Uns||En||Order|
|ВР5||~~WRe20||Delivery from the stock, in stock|
|ВР20||~WRe20||Delivery from the stock, in stock|
The well-known aphorism «everything is relative» illustrates how the quality of such alloys VR5 and VR20.
Heat resistance VR5 and VR20
Advantages of tungsten alloys is determined and rhenium. Tungsten — one of the most refractory, heavy metals and solid melts at t ° 3410 ° C, and boils at the same temperature as the surface of the sun: 6690 ° C. tungsten alloys in hardness and high melting point lead among others. Wolfram little inferior rhenium, with a melting point of 3170 ° C and 5870 ° C boiling point. Rhenium on the heat resistance of leaves far behind other metals showing high strength and resistance to corrosion.
Alloying tungsten 5% rhenium improves the ductility of the alloy increases the recrystallization temperature — this is especially important when using it for a positive electrode of the thermocouple. Using an alloy as the negative electrode of the thermocouple to maximize the thermoelectric power requires rhenium content to 35%, but not higher. Otherwise, at t ° to 1100 ° C the alloy uniformity is lost, and the thermoelectric power noticeably distorted. In the domestic industry rhenium additive does not exceed 20%, which allows the use of tungsten-rhenium thermocouples at t ° to 2500 ° C.
Tungsten-rhenium alloy exhibits resistance to helium, argon, dry nitrogen and hydrogen. SILICA alloying additives increases the stability of the alloy in the temperature range up to 2000 ° C in 2−3 times. Sensors VR5 / 20 are able to operate in a vacuum. For more efficient operation in a vacuum at 1800 ° C and higher should be used with larger diameter electrodes. VR5 / 20 is widely used as a differential thermocouple — may consist of two equal thermocouples connected, as a rule, opposite each other. These thermocouples are able to measure the level of temperature difference between two different junctions: the workers and contingent.
The nominal value of the thermoelectric power at lower temperatures up to 1600 ° C is also reduced to 24.59 mV At t = 1500 ° C, this indicator not more than 23,31 mV, and at t = 1400 ° C nominal level of thermo-emf is equal to 21.97 mV.
Disadvantages VR5 and VR20
The disadvantages of these alloys include poor reproducibility of the thermoelectric power, in view of what is required to group termoeletrodnye couple categories: A-1, A-2, A-3. Category A-1 allows the alloy to a maximum temperature 2200 ° C, temperature of use mode A-2 and A-3 is limited to 1800 ° C. It is strictly forbidden to use a wire from different parties, as each party wire has «its own» index of thermoelectric power. Tungsten and rhenium — rare metals, so their cost is very high. Price VR5 / 20 significantly exceeds the cost of thermocouples of others. Materials, but still less than the cost of optical pyrometers for the measurement and control of temperature modes in similar industrial environments.
The reaction of nitrogen and tungsten-rhenium alloy in vacuum conditions it is necessary to observe cleanliness and especially carefully follow the obligatory removing organic substances and dust.
VR5 and VR20 used for the manufacture of measuring and converting devices, contact sensors, thermocouple (TBP) for the measurement of very high temperatures in the steel industry — liquid metals. Up to 2500 ° C. measurement error is extremely small (± 0,01 ° C), which makes the TBP one of the most accurate instruments for measurements in such an aggressive environment.
The calibration table -termopar BAP-5 (BP-5) / BP-20 at t ° the free ends of 0 ° C Table Nominal static characteristic of BP transformation (A) -1.
|The temperature of the working end ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C||T.e.d.s.mV, Temperature, ° C|
1. Basic technical data
|Temperature ° C||Nominal value teds, mV||The deviation from the nominal teds, uV|
2. General information
Tungsten-rhenium wire thermocouples thermoelectrodes annealed graded nominal static characteristics conversion BP (A) -1 Wire meets technical conditions YaeO.021.142 specifications for the production of thermocouples BAP-5 (BP-5) / BP-20
3. Recommendations for use
Inadmissibility of the use of thermocouple thermocouple wire of different series, even with the same nominal static characteristic thermoelectrons.
Buy at the best price
In stock «Elektrovek-steel» company offers a wide range of thermocouples. Our offices are located in Russia and Ukraine. Making a purchase is possible, without leaving the office, through the Company’s website. To purchase just need to place your order and click «buy». If necessary, on any current problems you can consult our managers. They will provide all the necessary information regarding the products, price range, the implementation conditions. Lead times are minimal. When wholesale purchases discounts.Experience in the use of tungsten-rhenium thermocouples VR5 / 20 in the high thermometry