A/B Ratio & A/B-1 Draw Meters

GENERAL ORDERING INFORMATION:

Specify Meter Color & Digit Size, Meter Power and a Signal Conditioner from the list below. Specify Analog Output, Setpoint Output and Digital Interface if needed. These meters are shipped with a standard configuration and range shown below for each signal conditioner and output option type. All information for making changes is covered in the supplied Owners Manual. For other scalings or configurations, add the SC (Special Configuration) option.

DESCRIPTIONS:

The A/B ratio and A/B-1 draw meters are selectable operating modes of the Micro counter with Extended counter main board and FR dual-channel signal conditioner board.

• Ratio can be used to compare flow rates in two channels, the RPM of rollers or gears, or the speed of moving machinery, such as conveyor belts. Ratio can also be applied to scaled totals to compare two batches to be mixed. In this application, one meter is used to monitor the ratio of flow rates, and a second meter to monitor the resulting batch totals.

• Draw is obtained by subtracting 1 from ratio. Draw is often used to measure the elongation or shrinkage of material as it passes between rollers, or to monitor variation in the speed of rollers for tensioning.

Ratio and draw are similar, except that 1 is subtracted from ratio to obtain draw. The frequency of channels A and B is first measured and is then converted to rate in engineering units by multiplying it by the appropriate scale factor for that channel. Either rate can be displayed. The A/B ratio is then taken mathematically by the meter, and 1 is subtracted for draw. The result can be multiplied by a multiple or 10 from 0.0001 to 100000, and the decimal point can be set to display the result with the desired precision up to six digits.