Supported Applications
The Omega FR Series consists of ruggedized thin film Platinum Resistance Temperature Detector (RTD) elements sealed with cement in a cylindrical ceramic body. Designed for applications requiring high vibration resistance and temperature stability, these unhoused sensors are intended for dry environments only. Typical documented applications include analytical equipment, chemical plants, and mechanical equipment. The small tolerances on diameters facilitate problem-free installation within protective tubes.
Operating Conditions & Performance
The FR Series operates continuously across a temperature range of -70 to 500°C (-95 to 930°F). Elements meet IEC751, Class B tolerance standards with a Temperature Coefficient (TCR) of 3850 ppm/K. Long-term stability is specified as a maximum R₀-drift of 0.1% after 1000 h at 500°C (930°F). Insulation resistance exceeds 10 MΩ at 20°C (70°F) and remains above 1 MΩ at 500°C (930°F).
Response times vary by diameter, medium, and flow velocity. For the 2.8 mm (0.11") diameter element in water flowing at V = 0.4 m/s, response is 0.9 s to reach 50% and 2.7 s for 90%. In air at V = 1 m/s, the same dimension requires 12.3 s (50%) and 39.5 s (90%). The larger 4.5 mm (0.18") diameter element shows slower response: 1.5 s / 4.6 s in water and 24.8 s / 78.8 s in air under the same flow conditions.
Self-heating characteristics depend on nominal resistance and measuring current limits: for 100 Ω, max 3 mA; for 500 Ω, max 1.4 mA; and for 1000 Ω, max 1 mA. The series demonstrates vibration resistance of at least 40 g acceleration at 10 to 2000 Hz, and at least 100 g acceleration with an 8 ms half sine wave.
Configuration Options
The FR Series offers configurable nominal resistances, element counts, and physical dimensions. Selection is driven by the specific resistance value required, the number of elements per sensor body, and the diameter needed for installation constraints.
• Nominal Resistance: 100 Ω, 500 Ω, or 1000 Ω at 0°C (32°F).
• Element Count: Single element (e.g., 1PT) or dual element (e.g., 2PT) configurations.
• Diameter Options: 2.8 mm (0.11") or 4.5 mm (0.18").
• Housing Material: Ceramic body with platinum-clad nickel wire leads, 6.0 mm L (0.24").
• Overall Length: 8.0 mm (0.31") for all variants.
The measuring point for the basic value is situated 8 mm from the end of the sensor body. Dimensions are specified with a tolerance of ±0.3 mm.
Key Product Differences
Variants within the FR Series differ by nominal resistance, number of elements, and diameter, which directly influence self-heating coefficients and response times. Model numbers follow the pattern Nominal Resistance - Number of Elements - Diameter, such as 1PT100FR828 (single element, 100 Ω, 2.8 mm) or 2PT1000FR845 (dual element, 1000 Ω, 4.5 mm).
Self-heating values at 0°C vary by configuration: the 2.8 mm single-element models exhibit a self-heating of 0.05 K/mW for both 100 Ω and 1000 Ω resistances, while dual-element versions in the same diameter show 0.16 K/mW. The larger 4.5 mm diameter reduces self-heating to 0.04 K/mW (single element) or 0.08 K/mW (dual element), though this increase in size results in longer response times as noted above.
| Accuracy | Class B |
| Accuracy Detail | Class B per IEC60751 |
| Air Velocity, Max | 1 m/s |
| Insulation Resistance | > 10 MΩ |
| Insulation Resistance Note | >10 MΩ @ 20°C; >1 MΩ @ 500°C |
| Lead Material | Platinum Clad Nickel Wire |
| Long Term Stability | Max R/0-drift 0.1% after 1000 h @ 500°C |
| Operating Environment | Unhoused for dry environments only |
| Process Temperature, Max | 500 °C |
| Process Temperature, Min | -70 °C |
| Sensor Height | 8 mm |
| Series ID | 1PT100FR-RTD-ELEMENTS |
| Shock Resistance | 100 g Acceleration with 8 ms Half Sine Wave |
| Temperature Coefficient | 3850 ppm/K |
| Temperature Sensor Type | RTD |
| Vibration Resistance | 10 to 2000 Hz sweep rate, acceleration 40g |
| Water Velocity, Max | 0.4 m/s |
| Wire Length | 6mm |