PT100 Sensors

There are alot of hot melt hoses manufactures choosing PT100 heat sensors for their hot melt hoses. So what PT100 sensors offer to it’s customers?

PT100 are sensors are platinum resistance thermometers.They are offering highly accurance  temperature monitoring from –200  °C to +850 °C. They are getting this strenght fro their platinium core.

For a PT100 sensor, a 1 °C temperature change will cause a 0.384 ohm change in resistance, so even a small error in measurement of the resistance (for example, the resistance of the wires leading to the sensor) can cause a large error in the measurement of the temperature. For precision work, sensors have four wires- two to carry the sense current, and two to measure the voltage across the sensor element. It is also possible to obtain three-wire sensors, although these operate on the (not necessarily valid) assumption that the resistance of each of the three wires is the same.

PT100 sensors are comply following standartds: IEC751 and JISC1604-1989. Nordson, Melton and alot of manufacturer uses PT100 sensors in their hot melt hoses.

NTC Sensors

Robatech® Hoses are using NTC sensors for temperature measurement. NTC means negative temperature coefficient. Mainly used for resistive temperature and current-limiting devices. If you compare with silicon based temperature sensors and RTDs sensors, they are 5-10 times gives more accurate results. Range for the NTC sensors are −55°C to 200°C

RTD Sensors versus TC Series

Characteristic Thermocouple (T/C) Resistance Temperature Detector (RTD)
Measurement Range Wide, -250°C to +2600°C Narrower, -200°C to +850°C, often limited to a
lower temperature by its insulation.
Output Signal Voltage wrt difference in end-to-end
temperature
Resistance change wrt actual temperature
Accuracy Less accurate, 2-4°C typical More accurate, up to 1°C typical
Long Term Stability Fair, limited to shorter periods Good, stable over long periods
Stability/Drift Good, but more subject to drift Excellent, better long-term stability
Sensitivity Lower Higher sensitivity
Interchangeability Good Excellent
Linearity Fair linearity, special linearization
generally required.
Better linearity, special linearization still
required, but to a lesser degree
Self-Heating Error No self-heating error Some self-heating error, but low
Extension Cable High effect, must match T/C type
and is more expensive
Lower effect, can use different material, but
ultimately limited by lead wire resistance
Response Time Fast (≤ 0.1 seconds typical), but
CJC has thermal lag
Slower (1 to 7 seconds typical)
Repeatability Reasonable Better & greater standardization
Hysteresis Excellent Good
Signal Strength Low, prone to EMI Higher, more EMI resistant
Vibration/Shock Resistance Good resistance Less resistant than T/C
Robustness/Ruggedness Very good Good
Sensor Dimensions Very small to very large Small to medium
Measurement Area Small, single point-of-contact Larger, whole element must contact, 1” typical
Fine Wire Diameter Small down to 0.25mm diameter Larger up to 3mm diameter
Reference Junction Required and a significant source of
measurement error. Usually requires
a stable ambient at cold junction.
Not required and not a source of error
Excitation Required Not required, self-powered Yes, reference voltage or current source
Lead-Wire Resistance High, but often mitigated by mating
technology
Must be considered wrt maximum added
resistance and potential resistive imbalance
between leads
Cost Less expensive More expensive
Complexity Very simple and less subject to
mechanical stress
Physically larger and has a more complex
construction making it more subject to
mechanical stress
Calibration Ease More difficult and adds CJC
calibration
Less difficult, no CJC to contend with
Noise Immunity Lower noise immunity but often
mitigated by good wiring practice.
Small signals and high impedance
leads can easily pick up noise.
Better noise immunity than a T/C

Nordson compatible heated hose are using both sensors as follows;

Nordson® RTD Series Heated Hoses Nordson® TC Series Heated Hoses
Maximum Operating
Temperature (°C )
 232°C  232°C
Maximum Hydraulic
Pressure (psi)
 1000 psi 1500 psi
 Electrical Service  120 VAC, 200 VAC, 240 VAC  200 VAC, 230 VAC
 Avaliable Lenghts  up to 20 meter up to 13 meter