Accelerometers with a built-in amplifier (ICP), a Velocity Transducer or an Electromechanical Pick Up Sensor are input for the CMSS 530-100A-MR-ISO Velocity Module. The conversion of the pre-amplified wide-band raw signal to a standard ISO or non-standard velocity signal is done by filtering, integration and analog true RMS or True Peak conversion. The full-scale value for the velocity signal is converted to a 4-20 mA DC output current and can be further converted to a 1-5 V DC output voltage by using a 250-Ohm precision resistor.

The Monitor, option the derived velocity signal is compared with the alert and danger alarm level preset (set points). These set points are adjustable via two front panel accessible potentiometers, from 0 to 110% of full scale and directly measured on the BNC output connector of the monitor module. Each has an adjustable delay of 0.1 to 10 seconds. Relay contacts can be independently configured by the user for either Normally Open (NO) (standard) or Normally Closed (NC) operation. Relays are normally de-energized and can be configured for latching or non-latching (standard) operation. Latched alarms may be reset locally or by remote contact closure. Single Pole Single Throw (SPST) output relay contacts are rated 5 Amps at 30 Vdc or 125 Vac for resistive loads. The Monitor option also provides the Trip Multiply feature, basically a set point multiplication of either 2x or 3x via contact closure.

The second BNC connector mounted on the front of the Transmitter unit provides easy access to the buffered transducer output signal. This includes both the unfiltered vibration signal, and the DC bias voltage.

Portable test equipment or analyzers like the SKF Microlog can be connected to this output without disturbing other system outputs. The buffered transducer output signal is also available on the screw terminal connector for a permanent connection when needed.

Normally, the MCT module measures velocity signals from vibrations in a broadband according to ISO (International Standard Organization) Standards. ISO 10816-1 to ISO 10816-6 are the reference standards for the measurement and evaluation of vibration intensity levels. Standard Transmitters, like the 10 Hz to 1.0 kHz filter-module, are available with the Model Number extension ‘-ISO’.

Dependent on the type of machine and its rotational speed, other (non-ISO) filters with various corner frequencies from 2 Hz to 2.0 kHz in the broadband can be selected. Velocity is measured in Metric units (mm/s RMS) or in English units (in/s True Peak or RMS). The velocity signal directly relates to the vibration energy.
 

Sensitivity and Range Selection

To match the sensor signal output characteristics with the MCT module input sensitivity, the input signal is amplified by a jumper-selectable one of five fixed range values before it is processed. These jumper settings also define the full-scale range selection of the signal and the output level of the buffered velocity output signal.

The MCT CMSS 530-100A-MR-ISO Velocity is factory calibrated in Metric (mm/s RMS) or in English (in/s True Peak or RMS) units. This must be specified in the ordering code for the MCT module. The full scale range 2 is the factory preset.