Selected Aging Effects in Triaxial MEMS Accelerometers

Abstract

Natural aging of commercial triaxial low-g MEMS accelerometers, manufactured by surface micromachining, was evaluated in terms of changes of their offset voltages and scale factors, assigned to each sensitive axis. Two pieces of two models of triaxial accelerometers (ADXL 330 and ADXL 327 by Analog Devices Inc.) with analog outputs were tested within a period of ca. 4.5 years. Two different computer-controlled test rigs were used for performing relevant experimental studies, employing tilt angles as the reference source. Methodology of determining the proposed indicators of aging was based on cyclic repetition of the calibration procedure for each accelerometer. Changes of the output signals of the tested accelerometers were observed, resulting in respective indication errors of ca. 0.8% or even 2.2% while related to determining tilt. Since the accelerometers were operated under mild conditions while tested, much bigger errors are to be expected in the case of harsh conditions. Both pieces of ADXL 330 accelerometers ceased to operate properly within the testing period, approximately at the same time, for no apparent reason; thus, it is recommended to introduce redundancy in relevant reliable measuring circuits by doubling the number of the applied accelerometers.

Effects of Natural Aging in Biaxial MEMS Accelerometers

“…The maximal values of errors obtained for both types of accelerometers are much lower than the maximal value of 5% [20] found in the relevant publications. However, compare to the aging effects related to similar, yet triaxial, accelerometers (ADXL 330, ADXL 327), which we have reported recently, error values listed in Table III (1.2 -2.6% for ADXL 202E; 0.4 -1% for ADXL 203) are similar to their triaxial counterparts (0.4 -0.8%) [46], especially with regard to ADXL 203.…”

“…Combining Eq. (7)- (9) and (13), the relative maximal error M x..z of determining the acceleration corresponding to the full measurement range can be evaluated as [46]:…”

Electric-Contact Tilt Sensors: A Review

“…were observed, especially in the case of older biaxial models: the resultant errors were evaluated at even 2.6% [55]. Moreover, problems with respect to their reliability after few years of operation were reported in the case of newer triaxial acceleration sensors [56]. As far as long-term stability of electric contact tilt sensors is concerned, it can be stated that while employing high quality metallic materials typically used for electric terminals (both for the electrodes and the ball as well as their coatings), and assuming a standard operation of the sensor, a high long-term stability can be expected.…”

“…On the other hand, what may be surprising is that in the case of MEMS accelerometers, considerable aging effects were observed, especially in the case of older biaxial models: the resultant errors were evaluated at even 2.6% [ 55 ]. Moreover, problems with respect to their reliability after few years of operation were reported in the case of newer triaxial acceleration sensors [ 56 ].…”

Development of Synchronized High-Sensitivity Wireless Accelerometer for Structural Health Monitoring

“…The average current draw of Xnode with the M-A352 is 180 mA, as compared to some of the other standard WSSN platforms for SHM, such as the Martlet (Kane et al [20]) and Imote2 (Adler et al [45]) with 190 mA and 168 mA respectively. A study by Luczak et al [46] on the aging effects of MEMS accelerometers indicates that the changes to typical offsets and bias in these devices can be significant due to aging effects, especially under harsh operating conditions. The proposed method is expected to adapt to the actual working conditions of the sensor, such as operating temperature to give a better estimation rather than a nominal value, as it does not use any preset fixed delay values for the ADC delay characterization.…”