PRODUCT INFORMATION Double-Ended Tuning Fork Sensors OVERVIEW Statek has designed and manufactured quartz-crystal resonators using photolithographic and chemical milling methods for over three decades and has applied this expertise and capability to now offer double-ended tuningfork (DETF) force-sensors, as shown in Figure 1. Because the DETF force-sensors operate on frequencybased priniciples, they are immune to amplitude noise as well as noise at frequencies other than at the frequency of the sensor. As a consequence, the signals in the system can operate at full amplitude, thereby avoiding the noise that usually plagues low-level measurements. Quartz force-sensors offer further advantages over other force sensing technologies such as sensitivity, small size, low mass and stable performance. We can customize the size of the sensor to fit your application. FEATURES Highly sensitive Small size Operates based on frequency principles High signal-to-noise-ratio Figure 1: A picture of one of Statek’s DETF Force-Sensors 0 Frequency Shift (dF/F), ppm The resonant frequency of the DETF force-sensor is a function of its dimensions, electrode configuration, and the applied force. Compression or extension of the sensor causes a corresponding change in frequency, as shown in Figure 2. Once calibrated, measuring this change in frequency gives the applied force. -20,000 -40,000 -60,000 dF/F = DP + EP2 D = 124 ppm/gram E = 0.014 ppm/gram2 -80,000 -100,000 0 100 200 300 400 500 600 700 800 Applied Force (P), grams Figure 2: Example of a corresponding change in frequency by applied force. Low aging Designed for customer specific applications APPLICATIONS Accelerometers, see Figure 3. Pressure sensors, see Figure 4. Figure 3: Cross-section of one type of accelerometer. TECHNICAL PAPERS Chuang, Shih S., Force Sensor Using Double-Ended Tuning Fork Quartz Crystals, Proceedings of the 37th Annual Frequency Control Symposium, 1983, pp. 248-254. FURTHER INFORMATION We invite you to discuss your custom force sensing requirements with us. Call us at (714) 639-7810, or e-mail [email protected]. Figure 4: Schematic of pressure sensor or scale. 10186 - Rev A STATEK CORPORATION 512 N. MAIN ST., ORANGE, CA 92868 714-639-7810 FAX: 714-997-1256 www.statek.com