Identify the instrument and the reference<\/h2>\n
Record manufacturer, model, serial number, measuring range, resolution, specified accuracy and process connection. Include a clear photograph of the dial or display and identification label. A certificate should correspond to that serial number rather than a similar instrument stored in the same toolbox.<\/p>\n
For the reference instrument or calibration system, obtain its identification, applicable calibration record and capability for the intended range and medium. Do not select a reference solely because it displays more decimal places. Resolution describes the displayed increment; it does not establish the complete accuracy or uncertainty of the measurement.<\/p>\n
NIST’s metrological traceability policy<\/a> explains that traceability belongs to measurement results through documented calibration relationships and their uncertainty. A sticker or an unsupported claim of being NIST traceable does not, by itself, establish that a specific pump test has adequate measurement capability.<\/p>\n Check the instrument for visible damage, an unreadable scale, a damaged connection or signs of leakage. Record the as-found state before adjustment or repair and connect the instrument result to the pump maintenance inspection report<\/a>. A gauge showing damage may need a different disposition from one that is intact but overdue for verification.<\/p>\n Review recent exposure to overpressure, pulsation, vibration, temperature or incompatible fluid. Such events can justify investigation even when a scheduled calibration date has not arrived. Do not assume that a current certificate guarantees an instrument remains fit after a damaging event.<\/p>\n If the gauge is installed, arrange the site’s approved isolation and removal process. The HSE pressure-systems guide<\/a> provides general safety context for pressure equipment. Apply local requirements and the actual process procedure; stopping the pump does not prove that a gauge connection is free of pressure or hazardous liquid.<\/p>\n The calibration procedure should state the pressure medium, orientation, range, test points, stabilization criteria and ascending or descending sequences where required. Identify the conditions relevant to the instrument specification. A result obtained outside applicable conditions may not answer the intended acceptance question.<\/p>\n Record as-found readings before any permitted adjustment. If adjustment or repair is performed, retain that history and record the as-left results separately. Replacing the original data with the adjusted readings can conceal whether previous operating measurements need review.<\/p>\n Fluke’s process-gauge verification guidance<\/a> describes comparison with a reference and the need for a stable measurement setup. It is instrument guidance, not a requirement to use a particular brand or a universal calibration interval for pump-service gauges.<\/p>\n At a test point, indication error can be recorded as the instrument reading minus the reference value. Keep units consistent and state the sign convention. If the gauge reads 4.10 bar while the reference is 4.00 bar, the indication error is +0.10 bar in this hypothetical example.<\/p>\n Percentage statements require their denominator. For an assumed 0\u201310 bar instrument, an error of 0.10 bar is 1% of that span. The same numerical error is 2.5% of a 4.00 bar reading. Those percentages describe different bases and must not be substituted for each other when comparing against a specification.<\/p>\n The example demonstrates arithmetic only. It does not classify a gauge as acceptable or establish a pressure-test tolerance. Apply the actual instrument specification and the agreed decision rule, including measurement uncertainty where required. A measured error exactly at a limit should not be silently treated as having unlimited certainty.<\/p>\n Use the same evidence requirements when commissioning a contractor’s instruments. A certificate with a recent date but no clear relationship to the instrument, range or required decision can leave the test unresolved. Resolve that issue before the performance run consumes site time.<\/p>\n After calibration, check the actual connection, isolation arrangement and any impulse line or accessory against the approved measurement layout. The calibrated instrument is only one part of the installed chain. A blocked tapping, an unintended valve position or unsuitable connection can prevent it from measuring the intended pressure.<\/p>\n Document the reference elevation and units used in the pump test. When pressure readings contribute to a head calculation, include the liquid properties and other required terms. Do not subtract two readings with different pressure references or inconsistent units and label the result pump head.<\/p>\n![\"IS](\"https:\/\/borrapumps.com\/wp-content\/uploads\/2026\/10\/borra-realistic-20261016-img-025.webp\")
Inspect condition before collecting calibration data<\/h2>\n
Define the calibration conditions and sequence<\/h2>\n
Express errors without mixing percentage bases<\/h2>\n
Keep a usable calibration evidence table<\/h2>\n
\n\n
\n \nEvidence<\/th>\n What should be identifiable<\/th>\n Why it matters to the pump test<\/th>\n<\/tr>\n<\/thead>\n \n Instrument identity<\/td>\n Serial number, model, range and units<\/td>\n Connects the certificate to the installed gauge<\/td>\n<\/tr>\n \n Reference capability<\/td>\n Reference identity and applicable calibration<\/td>\n Establishes the basis of the comparison<\/td>\n<\/tr>\n \n Conditions<\/td>\n Medium, orientation and relevant environment<\/td>\n Defines when the recorded result applies<\/td>\n<\/tr>\n \n Test data<\/td>\n Reference value, indication and error<\/td>\n Preserves actual performance across the range<\/td>\n<\/tr>\n \n Intervention<\/td>\n As-found data and any adjustment or repair<\/td>\n Shows whether earlier readings require review<\/td>\n<\/tr>\n \n Result statement<\/td>\n Applicable tolerance, uncertainty and decision rule<\/td>\n Makes acceptance understandable<\/td>\n<\/tr>\n \n Service decision<\/td>\n Release, restriction or replacement<\/td>\n Prevents an unsuitable gauge returning to use<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n ![\"CYZ-A](\"https:\/\/borrapumps.com\/wp-content\/uploads\/2026\/10\/borra-realistic-20261016-img-019.webp\")
Review the installed measurement chain<\/h2>\n