Final answer:
There are several types of sensing techniques available for monitoring environmental temperature, including thermocouples, RTDs, and thermistors. For the PTC temperature sensor, the resistance at 85°C can be calculated using the resistance at 0°C and the temperature coefficient.
Step-by-step explanation:
There are several types of sensing techniques available for monitoring environmental temperature. Some of these include:
- Thermocouples: These sensors are made of two different metallic wires that generate a voltage in response to temperature changes. The voltage can be used to calculate the temperature.
- Resistance Temperature Detectors (RTDs): RTDs are made of pure metals whose electrical resistance changes with temperature. By measuring the resistance, the temperature can be determined.
- Thermistors: Thermistors are made of ceramic or polymer materials that have a highly nonlinear resistance-temperature relationship. The resistance can be measured to determine the temperature.
For the PTC temperature sensor, the resistance at 85°C can be calculated using the resistance at 0°C and the temperature coefficient. The temperature coefficient is given as 0.05 per degree Celsius. To calculate the resistance at 85°C, we can use the formula:
R = Ro * (1 + α * ΔT)
Where R is the resistance at 85°C, Ro is the resistance at 0°C, α is the temperature coefficient, and ΔT is the change in temperature. In this case, ΔT would be 85°C - 0°C = 85°C. Plugging in the values, we have:
R = 20 ohms * (1 + 0.05 * 85) = 20 ohms * 5.25 = 105 ohms