A sight-feed lubricator makes discrete lubricant drops visible so an observer can count them over time. This calculator converts a selected observation count and interval into a rate; it does not determine the lubrication requirement of any machine.
Sight-Feed Lubricator Observation Reference
Convert a counted sight-feed observation into rate, spacing and projection while viewing the connected oil path.
Equation Used
- The entered count and time describe one observation interval.
- The hourly count is a projection of that interval, not guaranteed future delivery.
- The selected reference maximum is not a verified product rating.
- Drop volume, oil properties, pressure, distribution, load and lubrication requirements are excluded.
When zero drops are observed, spacing is reported as 0 to indicate that no drop interval was observed.
Reservoir, metering needle and sight chamber
The illustration shows a gravity-fed oil cup with a screw-adjusted needle and a lower sight chamber. Oil passes around the needle tip and forms a drop at the nozzle before falling toward the threaded outlet. The needle opening is fixed in the illustration; counted drops do not specify an adjustment. Zero observed drops stops the drop display.
What the calculator determines
Enter drops counted, observation time and a selected reference maximum. The calculator reports observed drops per minute, observed seconds per drop, an hourly projection and percentage of the selected reference.
Observation arithmetic
Rate = 60N/t; spacing = t/N when N>0; hourly projection = 3600N/t; reference percentage = 100(rate/reference).
Selected-input arithmetic
Sixty drops counted in 60 seconds equal 60 drops/min, one second/drop and 3600 projected drops/hour.
Observation reference only
Drop volume, viscosity, temperature, pressure, oil grade, delivery continuity, downstream distribution, machine load and required lubrication rate are excluded. A zero spacing output means no spacing could be inferred because no drop was observed.
Questions
Does the hourly result guarantee delivery?
No. It is only a projection of the selected observation interval.
Is the reference maximum a product rating?
No. It is a user-selected comparison value.
Primary and authoritative references
- Gardner D. Hiscox, Mechanical Movements, Powers, Devices and Appliances (1901), page 335, figure 1386: sight-feed lubricator with screw-adjusted needle and sight opening.
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