Temperature Measurement
How to select a Temperature sensor
** Performance Consideration**
1.Determine the range of temperature to be measured.
2.Identify the operating media that is being measured.
3.Determine the temperature accuracy (+ or - Degree ,+ or - % of reading)
4.Determine frequency response required.
5.Identify the temperature units you require
Fahrenheit Celsius Kelvin Rankine Reaumure
6.Determine over-temperature conditions? Will temperature ever exceed maximum of range? By how much?
Mechanical Consideration
1.Physical Size
Size constraints Probe length Location access
2.Process connection/pressure fitting
What is the maximum working pressure of the system?
- Characteristics of the media
Corrosive Viscosity Velocity On/Off cycling
Electrical Consideration
1.Analog
mV /V 0-5 Vdc,0-10 Vdc,other Bipolar voltage Isolated or Non-isolated voltage 4-20 ma Current
2.Digital
RS485 RS232
3.Combination
Analog and Digital
4.Electrical Termination
Connector or integral cable Customer specified Need for mating connectors and cable assemblies Connector / Cable orientation Wiring codes / Pin-outs
5.External Zero and Span
6.Specify the type of power supply
Environmental Condition
1.Operating Temperature Range
2.EMI/RFI conditions
3.IP or NEMA rating required
4.Hazardous environment
Intrinsic safe Explosion proof
5.Indoor or Outdoor use
Exposure to the element Dust dirt Temperature extreme Animal,critters,rodents etc.
6.Submersible or Subsea
Depth Case pressure
Special requirement
- Calibration requirement
2.Special approval / Certifications
3.Testing or Cleaning
4.Special Labeling requirement
5.Shock and Vibration resistance
- Serviceability
How accessible must the unit be? How often will it be serviced?
