Match the field work to the question.
A hydrant flow test and a pressure recording are different observations. A flow test measures the system's response while water is discharged. A temporary pressure recorder documents how static pressure changes at an approved connection over a chosen period. Some projects need one; some need both.
Choose a hydrant flow test when the question is about supply under flow.
A flow test records static and residual pressure and outlet data during a planned discharge. Its report can show calculated flowing GPM and a projected water supply curve where appropriate. Engineering and fire protection teams may use these results to evaluate supply for a proposed project, subject to their design criteria and local review.
Typical question: “What did the water system deliver under the test conditions at this location?”
Choose 24 hour static pressure recording when the question is about one day's variation.
A temporary recorder can capture a full day and night of pressure observations at an approved connection. This can show changes that a single gauge reading at one moment would miss. The report identifies the recorded interval, location, pressure history, notable periods, and known limitations.
Typical question: “How did pressure vary across this particular day?”
Choose 7 day static pressure recording when the question needs a longer window.
A weeklong recording provides more opportunity to observe differences between days and operating periods. Its value depends on the location, sampling setup, and whether the chosen week represents the conditions the project team needs to examine.
Typical question: “How did pressure vary through several days of normal operation?”
What a static pressure recorder does not show
A static pressure history does not directly measure hydrant discharge capacity or replace a flow test required by a project team or AHJ. Similarly, one planned flow test is a snapshot under its recorded conditions; it does not describe every pressure change over a day or week.
What to send PFS: The location, the question you need answered, an approved recorder connection point if known, the desired observation window, access information, and the report deadline. We can help define the scope before scheduling.
Next step: Hydrant flow testing · 24 hour pressure recording · 7 day pressure recording.