MAINTENANCE
ALWAYS DISCONNECT PRIMARY POWER SOURCE BEFORE OPENING ENCLOSURE FOR INSPECTION OR SERVICE.
1 Frequent inspection should be made A schedule for maintenance checks should be determined by the environment and
frequency of use It is recommended that it should be inspected at least once a year
2 Perform visual, electrical and mechanical checks on all components on a regular basis
a Visually check for undue heating evidenced by discoloration of wires or other components, damaged or worn parts, or
leakage evidenced by water or corrosion in the interior
b Electrically check to make sure that all connections are clean and tight, and that the device is operating correctly
ADDITIONAL SCALING INFOOMATION
This information is supplied as a general introduction to the basic concepts used to scale rate displays The applicability of the
information is dependent on the type and capabilities of the specific display/monitor used
Flow meters producing an electronic signal are normally supplied in one of two output formats
• The pulse format generates some form of alternating signal that can be raw, that is no format amplification or wave
shaping can be done prior to transmission to the readout The output pulse rate is related proportionally to flow rate
Pulses can also be modified to produce higher output amplitudes or specific wave shapes
• The analog signal format is a continuous, variable voltage or current signal that is normally scaled to the dynamic range of
the meter Typical analog signals are 0…5V DC, 0…10V DC, and 4…20 mA The analog signals may or may not be derived
from a raw pulse signal produced by the flow meter
Scaling for any of these input signals always requires at least two scaling points for a linear process—zero or minimum flow
point and the maximum flow point
Additionally, each scaling point has two components, the actual input signal value and the preferred display value at that
input signal for that scaling point
For example, a pulse output flow meter has a flow of 50 gpm at a pulse rate of 100 Hz The actual input signal is the 100 Hz
figure, but allowing the display to read 100 would be meaningless to the operator The solution to this problem is to scale the
display to read 50 (gpm) when the input is 100 Hz
Maintenance
Page 14
March 2017
DSY-PM-00279-EN-03
