IMI SENSORS 699A07 User Manual

IMI Sensors: A PCB Piezotronics Div 699A07 User Manual
MAN-0192 rev A Page 29 of 39 800-959-4464
Typical Accelerometer & Velocity Sensor Checkout
Accelerometers & velocity sensors are tested by performing a frequency response
calibration. This is done by measuring the sensitivity of the sensor at a variety of
frequencies within its linear range. Per the ISO 16063-21 accelerometer calibration
standard, the amplitude at each frequency is at the discretion of the user and need
not be kept consistent. Best practice is to use amplitude safely above the noise floor
and but low enough not to create distortion on the shaker. Thus 1.0 g’s peak is the
most common amplitude used for 100 mV/g accelerometers.
The ISO 16063-21 standard recommends testing at the center frequencies of the
1/3 octave bands. For accelerometers with 10 kHz high frequency response that
would mean 29 different test points, which can be time consuming. Accelerometer
manufacturers test at far less points. In general as long as the test covers the
practical usage of the sensor and the test points are evenly dispersed through the
test range the user will perform a good and thorough test of an accelerometer.
A good practice within industrial applications is to follow the American Petroleum
Institute Standard 670 “Machinery Protection Systems” recommendations for
accelerometer and velocity sensor test points. Standard 670 recommends testing at
the following frequencies for both accelerometers and velocity sensors:
• 10, 20, 50, 61.44, 100, 200, 500, 1000, 2000, 5000 and 10000 Hz
o Model 699A07 is not capable of 61.44 Hz, only integer numbers such as
61 or 62.
For accelerometers the recommended amplitudes in API 670 are:
• 0.15 g’s peak (1 m/sec
2
RMS) for 10 Hz
• 1 g peak (7 m/sec
2
RMS) for 20-1000 Hz
• 4 g’s peak (30 m/sec
2
RMS) for 2000-10000 Hz
For velocity sensors the recommended amplitudes in API 670 are:
• 0.92 ips peak (15.92 mm/sec RMS) for 10 Hz
• 3.08 ips peak (55.70 mm/sec RMS) for 20 Hz
• 1.23 ips peak (22.28 mm/sec RMS) for 50 Hz
• 0.62 ips peak (11.14 mm/sec RMS) for 100 Hz
• 0.31 ips peak (5.57 mm/sec RMS) for 200 Hz
• 0.12 ips peak (2.23 mm/sec RMS) for 500 Hz
• 0.06 ips peak (1.11 mm/sec RMS) for 1000 Hz
• 0.12 ips peak (2.39 mm/sec RMS) for 2000 Hz
• 0.05 ips peak (0.95 mm/sec RMS) for 5000 Hz
• 0.02 ips peak (0.48 mm/sec RMS) for 1000 Hz
o Note that velocity is not recommended as a vibration measurement scale at
frequencies greater than 1000 Hz. Thus many sensor manufacturers install
low-pass filters on velocity sensors at 1000 Hz or lower.
Practical Industrial (Predictive Maintenance) Testing Recommendations
While testing to the API 670 or ISO 16063-21 standard is certainly thorough it is not
always practical and is time consuming especially for the predictive maintenance
user. Thus IMI Sensors makes the following recommendations for industrial
vibration:
• For permanent mount accelerometers/velocity sensors routed to an online
monitoring system or junction box, at least test the sensors at 1x and 2x running
speed and confirm both the vibration alert (high) and alarm (high-high).
• For route-based predictive maintenance where one sensor is magnetically mounted
on many machines at many points, perform a complete frequency response test of
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IMI SENSORS 699A07 Specifications

General

Brand	IMI SENSORS
Model	699A07
Category	Test Equipment
Language	English