X-Radiation Measurement Log (ANSI C37.85)

This template records X-radiation measurements taken at one meter during vacuum interrupter withstand testing. It captures the test setup, background and peak readings, the allowable emission limit, and whether the result passed or failed. Use it to create a consistent record for each test event and to document any deficiency or corrective action.

Complete it during or immediately after each withstand test so the readings, test voltage, duration, and observed conditions are captured while the event is still fresh. It is especially useful for commissioning, factory acceptance testing, maintenance verification, and troubleshooting after a suspected insulation or interrupter issue. Do not use it as a substitute for a full electrical test report when other test methods are required.

A qualified test technician, electrical engineer, or other authorized person familiar with vacuum interrupter testing should complete it. The person recording the readings should understand the test procedure, the meter setup, and the acceptance limit being applied. A competent person should also control the area and confirm that unauthorized personnel are excluded.

No. It is a documentation tool that supports compliance with applicable safety practices and test procedures, but it does not replace the underlying standard or site procedure. Use it alongside your electrical safety program, PPE requirements, lockout-tagout controls where applicable, and any manufacturer instructions. If your site has stricter limits or additional steps, those should be built into the template.

Common mistakes include recording only the peak reading without the background reading, failing to note the meter calibration status, and omitting the exact measurement distance. Another frequent issue is leaving out the test voltage or duration, which makes the reading hard to interpret later. The log should also capture any abnormal arcing, leakage, or equipment damage, even if the emission limit was not exceeded.

Use it every time a vacuum interrupter undergoes withstand testing where X-radiation monitoring is required by your procedure or risk controls. That may be during routine maintenance, acceptance testing, post-repair verification, or investigation of abnormal test behavior. If your program requires periodic trending, keep the completed logs together so repeated readings can be compared over time.

Yes. You can add fields for breaker model, test bay, operator name, meter serial number, calibration certificate reference, or site-specific emission limits. Many teams also add a sign-off line for a second reviewer or quality control check. Keep the one-meter measurement point and pass/fail comparison intact so the log stays consistent.

An ad-hoc note often misses one or more critical details, such as the allowable limit, background reading, or corrective action. This template standardizes the record so each test is documented the same way and can be reviewed later without guesswork. It also makes it easier to prove that the area was controlled and that the measurement was taken under defined conditions.