The SKF Machine Condition Indicator is an economical vibration sensor and indicator for monitoring non-critical machines. It is ideal for machinery with constant operating conditions not previously monitored in plants (fig 1). The device can be compared to the "check engine" light in a car. What the "check engine" light does for the car, the SKF Machine Condition Indicator does for industrial machinery. Internal sensors measure velocity, enveloped acceleration (bearing or gear impulsive vibration) and machine surface temperature.
The included magnetic read-key (fig 2) is used to activate the SKF Machine Condition Indicator, change operating modes, set vibration baselines and acknowledge alarms.
The unit features three LEDs to indicate the machine and bearing condition. Once the unit is illuminated, it alerts the predictive maintenance technician to do a root cause analysis on the machine. In addition, it features a barcode with serial number for machine identification purposes and easy incorporation into an Operator Driven Reliability (ODR) program, maintenance routes or scheduled check-ups.
The SKF Machine Condition Indicator is slightly larger than a standard industrial accelerometer. It is 68.3 mm (2.688 in.) in length and has a stainless steel base diameter of 33.7 mm (1.325 in.).
The enclosure is made of durable polymer. The interior is entirely sealed to environmentally protect the electronics and to achieve the highest ingress protection rating (IP 69K).
The stainless steel base on the bottom of the unit has 1/4-28 tapped threads for stud mounting.
What the “check engine” light does for the car, the SKF Machine Condition Indicator does for industrial machinery. Once the SKF Machine Condition Indicator is illuminated, it alerts the predictive maintenance technician to do a root cause analysis on the machine.
Internal sensors measure velocity, enveloped acceleration (bearing or gear impulsive vibration) and machine surface temperature.
A magnetic read-key is included to program the SKF Machine Condition Indicator. It is used to activate the SKF Machine Condition Indicator, change operating modes, set vibration baselines, acknowledge alarms, and reset the SKF Machine Condition Indicator.
The SKF Machine Condition Indicator features three LEDs that rotate and blink green, amber or red at various intervals and durations to indicate the current mode or alarm status.
If the alarm level is exceeded by a large amount, the SKF Machine Condition Indicator recognizes this and performs fewer verifications of the alarm condition before alarming. Stronger alarms display the red alarm LEDs sooner than weaker alarms, and all alarms are verified. Once the SKF Machine Condition Indicator has verified the alarm, red LEDs blink in a specific blink pattern according to the measurement type in alarm for a duration of one week.
Threshold mode (default mode)
In threshold mode, velocity and enveloping measurement results are compared to the following default alarm threshold levels, which are applicable to most “standard” machinery running at constant speeds from 900 to 3 600 r/min:
- Velocity: 9,0 mm/s rms (0.35 in./s rms; 0.5 in./s equivalent peak)
- Enveloped acceleration: 4 gE
- Temperature: 105 °C (220 °F)
Percentage mode
In percentage mode, the SKF Machine Condition Indicator establishes a baseline value (norm) for the machine’s velocity and enveloped acceleration vibration levels. These machine measurement results are compared to a multiple of the established baseline value:
- Velocity: 2 × baseline value (200%)
- Enveloped acceleration: 2 × baseline value (200%)
- Temperature: Baseline value plus 50 °C (90 °F)
The SKF Machine Condition Indicator sleeps most of the time. When it is asleep, it conserves battery power. It wakes up at a preset interval to take measurements eight times per day. Once activated, the SKF Machine Condition Indicator immediately starts taking measurements and evaluates the current vibration level of the machine. If the level does not meet minimum alarm threshold levels, the SKF Machine Condition Indicator goes back to sleep to eliminate taking data when the machine is off.
Verification
If the SKF Machine Condition Indicator detects an alarm condition, it automatically verifies the alarm condition by retrying its measurements. This helps rule out transient conditions and false alarms.
Adaptive alarming
If the alarm level is exceeded, the SKF Machine Condition Indicator verifies the alarm condition within 2 to 12 hours. If the signal goes above the level by only a small amount, the SKF Machine Condition Indicator will verify the condition for a maximum of 12 hours before it displays the red alarm LEDs.
Benefits
- Provides a simple, low cost solution to determine the basic machine health on assets not necessarily being monitored
- Frees up time to concentrate on root cause analysis or maintenance instead of problem detection
- Non-critical machine routes could be more widely spaced, e.g., every other month instead of monthly, with the SKF Machine Condition Indicator installed and replaced by a simple, quick check of the LEDs