Miniature Triaxial DeltaTron® Accelerometer Type 4504-A is a triaxial piezoelectric ThetaShear® (patented) accelerometer with three independent outputs for simultaneous high-level measurements in three mutually perpendicular directions. Each transducing element is individually calibrated.
Type 4504-A features three separate and rugged 10 –32 titanium connectors. It has 3 mm threaded holes for mounting with M2 screws or M3 studs.
The piezoelectric element used is the PZ 23 lead zirconate titanate element. The housing is aluminium.
用途
- General purpose accelerometer
特徴
- Triaxial
- Low weight
- High sensitivity to weight ratio
- Low sensitivity to environmental factors
- High resonance frequency
- Clip mounting
Characteristics
DeltaTron® accelerometers operate on a constant-current power supply and give output signals in the form of voltage modulation on the power supply line.
The ThetaShear design involves a slotted cylindrical stanchion holding a central seismic mass, flanked by two piezoelectric plates. This assembly is clamped rigidly by the cover. To ensure optimum accuracy and reliability, no bonding agent other than molecular adhesion is required to hold the assembly together. The ThetaShear design provides for a combination of highest measurement stability, excellent sensitivity-to-weight ratio and low sensitivity to extraneous environmental effects.
A remarkable feature of the ThetaShear principle is the fact that the transverse resonance frequency will always be found outside the 10% frequency limit. This ensures minimum interference from orthogonal vibration components in the useful frequency range of the accelerometer. The ThetaShear design also provides excellent immunity to other environmental effects such as base strains, magnetic sensitivity and acoustic fields.
Mounting
Special effort has been put into making mounting as flexible as possible. For fast and easy mounting, Mounting Clips UA 1408, UA 1473 and UA 1474 can be used. Five of the six surfaces can be used for mounting with adhesive cement or mounting wax. Where threaded holes can be provided in the test piece, Type 4504 A can be mounted from the top via mounting holes in the base. The base can accommodate three M2 screws for top mounting.
When using miniature accelerometers, the accelerometer cable can affect the measurement result because of forces exerted by the cable on the accelerometer connector. This can then cause amplitude irregularities in the output from the accelerometer at frequencies up to approximately 200 Hz. This can be reduced by using a flexible cable. To effectively reduce the problem at low frequencies, it is generally recommended to clamp the cable. One way of doing this is to make a small loop in the cable close to the accelerometer (max. diameter 30 mm) and clamp the cable beside the base of the accelerometer with mounting wax or double-sided tape. This also reduces the possibility of dynamically induced noise generated by the cable.
Calibration
The sensitivity given in the calibration chart has been measured at 159.2 Hz with an acceleration of 10 g. For a 99.9% confidence level, the accuracy of the factory calibration is ± 2%.
