Temperature Sensor Technical Brief
Introduction
RF Code offers three temperature-sensing products, the R150, R151 and R155. This document explains the accuracy and precision of these products and defines their context for usage in the data center. The following table shows the temperature sensor accuracy for typical use and over the entire supported temperature range.
| Sensor Product | Accuracy | Range Fahrenheit | Range Celsius | |
|---|---|---|---|---|
| Temperature Sensor R150-5B10 | Typical Range of Use | ± 1° F | +40° to +140° | +5° to +60° |
| Entire Supported Range | ± 1.5°F | -4° to +158° | -20° to +70° | |
| Tethered Temperature Sensor R151-0010 | Typical Range of Use | ± 2° F | +14° to +185° | -10° to +85° |
| Entire Supported Range | ± 4° F | -67° to +212° | -55° to +100° | |
| Humidity & Temperature Sensor R155-5B10 | Typical Range of Use | ± 0.4°F | +50°to +140° | +10° to +60° |
| Entire Supported Range | ± 2° F | -4° to +158° | -20° to +70° |
Sensor Precision
Sensor Calibration
All of these products (R150, R151 and R155) have temperature-sensing components that are calibrated at the factory during the manufacturing process. These are silicon-based chips that don’t require field calibration or re-calibration over time. As the ambient temperature moves toward the extremes, sensor accuracy decreases.
The precision of the reported temperature data is also important. Temperature sensor data is handled by multiple RF Code components as part of the overall solution. The R150, R151 and R155 collect the data and transmit it via 433 MHz RF to RF Code readers. RF Code software (Zone Manager or Asset Manager) then collects the data from the readers. The following table shows the data precision for each product.
| Sensor Product | Precision at the Reader | Default Precision in the Software |
|---|---|---|
| Temperature Sensor R150-5B10 | 0.06° C | 0.1° C * See note below |
| Tethered Temp Sensor R151-0010 | 0.5° C | 0.5° C * See note below |
| Humidity & Temp Sensor R155-5B10 | 0.04° C | 0.1° C * See note below |
Note: Temperature precision can be controlled in the RF Code software via configuration settings to allow for less precision and therefore reduce the number of data points and fluctuation in values.
Sensor Performance in the Data Center
Data center temperatures typically range from about 60° to 110° F (15° to 45° C) with a relative humidity range of 30% to 60% RH. In this environmental range, the sensors for the R150, R151 and R155 deliver their best, most accurate performance. This is true because the calibration coefficients are selected to ensure the most accurate readings in this specific range. The most accurate sensor is the R155 Humidity & Temperature Sensor that provides better than one quarter of one degree Celsius accuracy in the typical data center temperature range, including allowance for quantization error.
| Sensor Product | Accuracy (typical) | Ambient Range |
|---|---|---|
| Temperature Sensor R150-5B10 | ± 0.47°F | +50°to +140°F |
| Temperature Sensor R150-5B10 | ± 0.26°C | +10°to +60°C |
| Tethered Temperature Sensor R151-0010 | ± 1.08°F | +50°to +104°F |
| Tethered Temperature Sensor R151-0010 | ± 0.60°C | +10°to +40 C° |
| Humidity & Temperature Sensor R155-5B10 | ± 0.41°F | +50°to +140°F |
| Humidity & Temperature Sensor R155-5B10 | ± 0.23°C | +10°to +60°C |
| Humidity & Temperature Sensor R155-5B10 | ± 2% RH | 10% to 90% RH at 25°C |
Conclusion
The RF Code R150, R151 and R155 temperature-sensing products are ideally suited for monitoring data center temperature performance. The highly accurate nature of these sensors in the data center environment allow for fine-grained monitoring and reporting.
Legacy Products (First Generation)
| First Generation Sensor Product | Accuracy (typical) | Range Fahrenheit | Range Celsius |
|---|---|---|---|
| Temperature Sensor R150-0B10 | ± 2° F | +14 °to +158° | -10°to +70° |
| Temperature Sensor R150-0B10 | ± 4° F | -4°to +158° | -20°to +70° |
| Humidity & Temperature Sensor R155-0B10 | ± 2° F | -4°to +158° | -20°to +70° |
| First Generation Sensor Product | Precision at the Reader | Default Precision in the Software |
|---|---|---|
| Temperature Sensor R150-0B10 | 0.5° C | 0.5° C * See note below |
| Humidity & Temp Sensor R155-0B10 | 0.04° C | 0.1° C * See note below |
Note: Temperature precision can be controlled in the RF Code software via configuration settings to allow for less precision and therefore reduce the number of data points and fluctuation in values.
| First Generation Sensor Product | Accuracy (typical) | Ambient Range |
|---|---|---|
| Temperature Sensor R150-0B10 | ± 1.08°F | +50°to +104°F |
| Temperature Sensor R150-0B10 | ± 0.60°C | +10°to +40°C |
| Humidity & Temperature Sensor R155-0B10 | ± 0.77°F | +50°to +104°F |
| Humidity & Temperature Sensor R155-0B10 | ± 0.43°C | +10°to +40°C |
| Humidity & Temperature Sensor R155-0B10 | ± 2% RH | 10% to 90% RH at 25° C |