bulletเทอร์โมคัปเปิล Thermocouple อาร์ทีดี RTD Pt100
bulletTemperature Controller
bulletThermocouple Head Explosion Proof,XDA
bulletThermocouple Head Explosion Proof,XDS
bulletINOR-Transmitter Thermocouple and RTD,PT100
bulletเทอร์โมคัปเปิล แบบหัวเกลียว M6 และ 1/2
bulletเทอร์โมคัปเปิล แบบหางปลากลม 5,6,7,
bulletเทอร์โมคัปเปิลมาตรฐาน ออกสาย
bulletเทอร์โมคัปเปิลมาตรฐาน ออกสาย+สปริง
bulletเทอร์โมคัปเปิลพร้อมเกลียวมาตรฐาน 2,3,4,6,8 หุน
bulletเทอร์โมคัปเปิลแบบเขี้ยวล็อค 1
bulletเทอร์โมคัปเปิลแบบเขี้ยวล็อค 2
bulletเทอร์โมคัปเปิล type K
bulletเทอร์โมคัปเปิล type J
bulletเทอร์โมคัปเปิล type T
bulletเทอร์โมคัปเปิล type E
bulletเทอร์โมคัปเปิล type B
bulletเทอร์โมคัปเปิล type R
bulletเทอร์โมคัปเปิล type S
bulletเทอร์โมคัปเปิล type N
bulletทฤษฎีเทอร์โมคัปเปิล จาก wiki
bulletThermocouple Type K
bulletThermocouple Type J
bulletThermocouple Type T
bulletThermocouple Type E
bulletThermocouple Type B
bulletThermocouple Type R
bulletThermocouple Type S
bulletThermocouple Type N
bulletPT100 Diameter1.5mm
bulletPT100 Diameter3mm
bulletPT100 Diameter3.2mm
bulletPT100 Diameter4mm
bulletPT100 Diameter5mm
bulletPT100 Diameter 6mm
bulletPT100 Diameter6.3mm
bulletPT100 Diameter 7mm
bulletPT100 Diameter 8mm
bulletPT100 Diameter9.5mm
bulletPT100 Diameter 10mm
bulletPT100 Diameter 10.2mm
bulletPT100 Diameter 12.7mm
bulletPT100 Diameter 15.8mm
bulletPT100 Diameter 17.5mm
bulletPT100 Diameter 19mm
bulletPT100 Diameter 22mm
bulletPT100 Diameter 25.4mm
bulletPT100 wire PVC
bulletPT100 wire TEFLON
bulletPT100 wire Silicone
bulletPT100 wire 1m
bulletPT100 wire 2m
bulletPT100 wire 3m
bulletPT100 wire 4m
bulletPT100 wire 5m
bulletPT100 wire 6m
bulletPT100 wire 7m
bulletPT100 wire 8m
bulletPT100 wire 9m
bulletPT100 wire 10m
bulletOther PT100
bullet3 Wire RTD Sensor
bullet4 Wire RTD
ฮีตเตอร์ , HEATER
bulletฮีตเตอร์ , HEATER
bulletอินฟราเรด ฮีตเตอร์
bulletOMEGA Thermocouple

ฮีตเตอร์ อุตสาหกรรม เทอร์โมคัปเปิล

OMEGA Thermocouple

OMEGA Thermocouple

Navigation image map


สินค้า OMEGA  ประเทศไทย จัดจำหน่ายโดย บริษัท ไออีเอส อิเล็คทริค จำกัด  โทร.02-1011230-2 แฟ็กซ์. 02-1011233

Thermocouple imageThermocouples - An Introduction
What is a thermocouple sensor?
A thermocouple is a sensor for measuring temperature. It consists of two dissimilar metals, joined together at one end. When the junction of the two metals is heated or cooled a voltage is produced that can be correlated back to the temperature. The thermocouple alloys are commonly available as wire.

What are the different thermocouple types?
A thermocouple is available in different combinations of metals or calibrations. The four most common calibrations are J, K, T and E. There are high temperature calibrations R, S, C and GB. Each calibration has a different temperature range and environment, although the maximum temperature varies with the diameter of the wire used in the thermocouple. Although the thermocouple calibration dictates the temperature range, the maximum range is also limited by the diameter of the thermocouple wire. That is, a very thin thermocouple may not reach the full temperature range. to view a complete reference table for each thermocouple. The table includes international color codes for thermocouple alloys, temperature range and limits of error for almost every kind of thermocouple.
How do I choose a thermocouple type?
Because a thermocouple measures in wide temperature ranges and can be relatively rugged, thermocouples are very often used in industry. The following criteria are used in selecting a thermocouple:

  • Temperature range
  • Chemical resistance of the thermocouple or sheath material
  • Abrasion and vibration resistance
  • Installation requirements (may need to be compatible with existing equipment; existing holes may determine probe diameter)

How do I know which junction type to choose?
Sheathed thermocouple probes are available with one of three junction types: grounded, ungrounded or exposed (see graphic below:"Thermocouple Tip Styles"). At the tip of a grounded junction probe, the thermocouple wires are physically attached to the inside of the probe wall. This results in good heat transfer from the outside, through the probe wall to the thermocouple junction. In an ungrounded probe, the thermocouple junction is detached from the probe wall. Response time is slower than the grounded style, but the ungrounded offers electrical isolation (see table below).

Room-Temperature Insulation Resistance
Ungrounded Thermocouple
Nominal Sheath Diameter Applied dc Voltage min. Insulation Resistance min.
Less than 0.90mm (0.03in.) 50V 100M Ohms
0.80-1.5mm (0.030 to 0.059in.) 50V 500M Ohms
Greater than 1.5mm (0.059in.) 500V 1000M Ohms
The thermocouple in the exposed junction style protrudes out of the tip of the sheath and is exposed to the surrounding environment. This type offers the best response time, but is limited in use to dry, noncorrosive and nonpressurized applications.

What is response time?
A time constant has been defined as the time required by a sensor to reach 63.2% of a step change in temperature under a specified set of conditions. Five time constants are required for the sensor to approach 100% of the step change value. An exposed junction thermocouple is the fastest responding. Also, the smaller the probe sheath diameter, the faster the response, but the maximum temperature may be lower. Be aware, however, that sometimes the probe sheath cannot withstand the full temperature range of the thermocouple type.

Material Maximum Temperature Application Atmosphere
Oxidizing Hydrogen Vacuum Inert
304 SS 900°C (1650°F) Very Good Good Very Good Very Good
Inconel 600 1148°C (2100°F) Very Good Good Very Good Very Good

Thermocouple Ranges and Limits of Error
The table below shows temperature ranges and accuracy for J, K, E and T thermocouples. Click here for additional thermocouple types.

Chart of common thermocouple temperature ranges

Thermocouple Types
Beaded Wire Thermocouple Beaded Wire Thermocouple
A beaded wire thermocouple is the simplest form of thermocouple. It consists of two pieces of thermocouple wire joined together with a welded bead. Because the bead of the thermocouple is exposed, there are several application limitations. The beaded wire thermocouple should not be used with liquids that could corrode or oxidize the thermocouple alloy. Metal surfaces can also be problematic. Often metal surfaces, especially pipes are used to ground electrical systems The indirect connection to an electrical system could impact the thermocouple measurement. In general, beaded wire thermocouples are a good choice for the measurement of gas temperature. Since they can be made very small, they also provide very fast response time.

Thermocouple Probe
Thermocouple Probe
A thermocouple probe consists of thermocouple wire housed inside a metallic tube. The wall of the tube is referred to as the sheath of the probe. Common sheath materials include stainless steel and Inconel. Inconel supports higher temperature ranges than stainless steel, however, stainless steel is often preferred because of its broad chemical compatibility. For very high temperatures, other exotic sheath materials are also available. View our line of high temperature exotic thermocouple probes.
The tip of the thermocouple probe is available in three different styles. Grounded, ungrounded and exposed. With a grounded tip the thermocouple is in contact with the sheath wall. A grounded junction provides a fast response time but it is most susceptible to electrical ground loops. In ungrounded junctions, the thermocouple is separated from the sheath wall by a layer of insulation. The tip of the thermocouple protrudes outside the sheath wall with an exposed junction. Exposed junction thermocouples are best suited for air measurement.

Thermocouple Tip Styles
Grounded Thermocouple Ungrounded Thermocouple Exposed Thermocouple
Grounded Thermocouple Ungrounded Thermocouple Exposed Thermocouple
thermocouple Surface Probe Surface Probe
Measuring the temperature of a solid surface is difficult for most types of temperature sensors. In order to assure an accurate measurement, the entire measurement area of the sensor must be in contact with the surface. This is difficult when working with a rigid sensor and a rigid surface. Since thermocouples are made of pliable metals, the junction can be formed flat and thin to provide maximum contact with a rigid solid surface. These thermocouples are an excellent choice for surface measurement. The thermocouple can even be built in a mechanism which rotates, making it suitable for measuring the temperature of a moving surface. Type K is ChromegaAlomega.


Copyright © 2010 All Rights Reserved.
เลขทะเบียนพาณิชย์อิเล็กทรอนิกส์ เลขที่ 0135549007974 IES ELECTRIC CO.,LTD. 56/242 moo5 ,Lardsawai,Lum Luk Ka,Patumthani.12150 บริษัท ไออีเอส อิเล็คทริค จำกัด 56/242 หมู่5 ต.ลาดสวาย อ.ลำลูกกา จ.ปทุมธานี 12150 TEL:(02)-1011230-2 FAX:(02)-1011233 Mobile : (086) 3114992 e-mail:
ดู TEMPERATURE CONTROLLER,LINKING,เครื่องควบคุมอุณหภูมิ ในแผนที่ขนาดใหญ่กว่า