Sensors

FURTHER INFORMATION
We invite you to discuss your custom force sensing
requirements with us. Call us at (714) 639-7810,
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.
Figure 4: Schematic of pressure sensor or scale.
Figure 3: Cross-section of one type of accelerometer.
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.
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.
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.
STATEK CORPORATION 512 N. MAIN ST., ORANGE, CA 92868 714-639-7810 FAX: 714-997-1256 APPLICATIONS
Accelerometers, see Figure 3.
Pressure sensors, see Figure 4.
PRODUCT INFORMATION
Double-Ended Tuning Fork Sensors
10186 - Rev A
Figure 1: A picture of one of Stateks DETF Force-Sensors
FEATURES
Highly sensitive
Small size
Operates based on frequency principles
High signal-to-noise-ratio
Low aging
Designed for customer specific applications
Figure 2: Example of a corresponding change in frequency by applied
force.
-100,000
-80,000
-60,000
-40,000
-20,000
0
0 100 200 300 400 500 600 700 800
Applied Force (P), grams
Frequency Shift (dF/F), ppm
dF/F = P + P2
= 124 ppm/gram
= 0.014 ppm/gram2