Nutech Engineers
143-D Government Industrial Estate, Kandivli West, Mumbai - 400 067
Phone : 91-22-28683549 / 28684580,  Fax : 91-22-28674580
email : nutechen@vsnl.com , nutechen@mtnl.net.in,
info@nutechengineers.com,  sales@nutechengineers.com

Temperature Sensing Devices

Resistance Temperature Detectors (RTD) are sensors for indicators, recorders and / or controllers.  The sensor is a wire would element of copper, nickel or platinum.  A temperature change causes a linear resistance change throughout the range of the sensor.  Accuracy of .25% and .10% sensors are offered.  A three wire system is commonly used to minimize offsets due to extension lead wire lengths and temperatures.  On a two wire system a 25 foot copper extension wire causes a small offset.

Element Resistance & Coefficient

• Platinum, 100 Ohms Bulb .00385 Ohms/Ohms/^oC

Accuracy and Temperature Rating

• Pt. .25% Accuracy 260^oC Maximum

• Pt. .1% Accuracy 260^oC Maximum

• Pt. .25% Accuracy 500^oC Maximum

• Pt. .1% Accuracy 500^oC Maximum

• Cu. .1% Accuracy 150^oC Maximum

Element Configuration

• Single Element, 3 wire

• Dual Element, 3 Wire

• Single Element 2 Wire

• Dual Element 2 Wire .25% Only

Effects of Copper Lead wire for a 2 wire RTD per 10 Feet at 38^oC copper or Platinum Element

Platinum wire, 100 Ohms at (0^oC) Temperature Coefficient of Resistance for the range 0-100^oC is .00385 Ohms/Ohms/^oC, DIN 43760.  Copper wire 88.28 Ohms at 0^oC range -150^oC to +150^oC.

Repeatability 

 +/- .08^oC or better over full range

Stability  

Drift is less than +/- .08^oC at 0^oC after one year normal service within rated temperatures.

Time Constant 

 5 seconds in water at 3 feet / second

Insulation Resistance 

10 Mega ohms minimum at 100 Vdc.  Leads to case at room temperature

Vibration 

Assembly construction withstands 50 H_z at 20 G's minimum per MIL-STD-220C.  Method 204A, Test Condition D.

Shock

Element construction withstands minimum 100 G's sine wave shock of 3 millisecond duration, three blows applies to each axis.