> Products  > Temperature sensor > Standard Thermocouples - Straight Type with Protection

General

Standard Thermocouples - Straight Type with metal and ceramic protection tubes are used for temperature measurement technology, primarily in furnaces of all kinds, in the temperature range of about 200 ° C to 1800 °C at pressures up to max. 1 bar (Nenndruckstufe 1).

Structure and types of election

Um die Funktion eines Thermoelementes über einen angemessenen Zeitraum zu gewährleisten, müssen die Werkstoffe für Thermopaar, Isolation, Schutzrohr und Anschlußkopf nach den Betriebsbedingungen ausgewählt werden. To the function of a thermocouple over a reasonable period to ensure the materials for thermo couple, insulation, protective tube and connector head to the operating conditions are selected.

General advice on thermo couple and protective pipe materials can be found in DIN 43712, DIN 43720, DIN 43724 and DIN 43732. DIN 43720 as well as in literature.

The catalog specified Temperatures are recommended for use in air. Short-term exceedances of these temperatures are acceptable, however, shorten the life span. Particularly corrosive influences, the allowable operating temperature of the protective pipe materials performance.

Thermo-couple standards

The thermocouple voltages are

· DIN IEC 584 Tolerance Class 1 or

· DIN 43719 DIN 43719

If desired, other elements according to standards and tolerances can be supplied.

Attention:

For the thermocouple Fe-CuNi couple of new plants is just the type J according to DIN IEC 584 permitted. The core values differ from the previous type L according to DIN 43710, which is only to replace existing measuring systems to be used.

If the standard is not the desired standard, please call our variant.

Through the introduction of DIN IEC 584, the basic value of the series ANSI MC 96.1-82 are identical with the BS 4937, NFC-321 and JIS 1602-81.

The type of the thermocouple pair is built on the shield of the connector head indicated.

Protection tubes

The outer protection tubes according to the criteria of stability under the operating conditions selected, see Table 1. Instructions can be found in DIN 43720 and in DIN 43724.

Table 1

Resistant metal protective pipe materials:

· 35.8 WNr St. 1.0305
temperatures of max. 550 °C in air. Low resistance to sulphurous gases, medium resistance to nitrogen gases
· 35.8 WNr St. 1.0305 – feueremalliert
for temperatures of max. 550 °C, 1 bar gauge pressure for the low pressure area in the furnace, flue gas ducts and vessels
· X10Cr Al 24 WNr. 1.4762
for temperatures of max. 1200 °C in air. Major resistance to sulfur gases, low resistance to nitrogen gases
· X18Cr Ni 28 WNr. 1.4749
for temperatures of max. 1100 °C in air. Extremely high resistance to sulfur gases, low resistance to nitrogen gases, good resistance to lead and Zinnsmelting
· X15 CrNi Si WNr 2520. 1.4841
for temperatures of max. 1150 °C in air. Low resistance to sulphurous gases, great resistance to low-oxygen-nitrogen gases, high creep resistance

For extreme Korrisionsbedingungen can protect pipes made of special materials are delivered from, for example:

· WNr. 1.4571, 2.4816, 2.4858, 2.4610, 2.4617,titanium, tantalum, etc.
· Copper or steel, Tantalum Plating
· Steel or non. Steel with Teflon coating
· Protection against abrasion for different temperature ranges
· KER 710 with ceramic coating made of platinum or platinum alloy (especially for Gassmelting)

The lifetime of thermal couples will in many cases, increased if, in addition to the outer protective tube gas-tight ceramic inner tube is inserted.

Properties of the ceramic types according to DIN 40685 for protective tubes and inner tubes:

KER 530: feinporös, not gas density, thermal shock resistance, high alumina content> 80%, max. Temp. 1650 °C

KER 610: gas density, high fire resistance, high alumina content> 60%, max. Temp. 1600 °C

KER 710: gas density, high fire resistance, pure aluminum oxide> 99.7%, max. Temp. 1900 °C 

Connection heads

Depending on the operating conditions are 5 different designs with connecting dimensions according DIN 43729 are available.

All models are water resistant, protection class IP 53.

Ambient temperature max. 200 ° C or 120 ° C for plastic.

Fixing

The thermocouples of this catalog are usually a sliding Anschlagflansch or a threaded sleeve mounted sliding.

Mounting instructions

The main points in the assembly are:

· The installation length of the thermocouple elements is as large as possible to choose, so measurement error due to heat dissipation in the protective tube and the thermocouple wires are kept as small as possible.
· To the deflection mainly long protective tubes, to avoid vertical mounting the horizontal preferred, or there are appropriate supports must be provided.
· For the connection cable between the thermocouple wires within the connector head and the display instrument balance lines must be used.
· It is important to ensure that the right pair of thermocouple compensating cable elected and polarity is correct.

Delivery

The product group includes straight thermocouples 4 basic types.

When the guy with metal protective tube are built from pairs of thermocouples Unedelmetallen included in the list.

For types with ceramic protection tubes are the precious thermal couples are fitted at the time of delivery, but not included in the list. Because of the varying price of precious metals, they are considered as a separate invoice item.

Standard designs

Standard designs are selected most often applied thermocouples. They are available from stock and are also in small quantities cheaply available. Fasteners are available as accessories to be ordered separately.

Variants

Variants broaden the scope of the standard models by altering the dimensions or materials. This allows thermocouples in practical use widely different operating conditions.

Maximum operating temperature of thermocouple pairs

The elected or thermo-couple protection tube material with the smaller allowable operating temperature determines the max. operating temperature of the thermocouple.

If a different mounting than the desired resting on the flange, it is as an accessory to be ordered separately.

Special designs

Special designs are available in many shapes and materials available.

Examples of special designs are:

· Thermo couples to other standards
· with special protective tube and attaching the pipe materials
· Thermocouples with different dimensions
· Thermocouples with specially trained monitoring points, for example, in the ground wrapped or exposed measurement site

To edit a question on special models, we need:

· a detailed description of the measuring, possibly accompanied by sketches on the installation conditions,
· the drawing with all material information, if necessary in the construction of the thermocouple has already been determined,
· an indication of the subscription or order number, if previously a similar special version has been purchased from ourselves.

Items

Many components of catalog types may also be components or assemblies may be paid. They are delivered in containers.

Gerade Thermoelemente - Typenübersicht

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