зафиксировать

In a sentence

• Я зафиксировал дату встречи в календаре.

  I recorded the meeting date in the calendar.

  Here, "зафиксировать" is used to mean 'to record or note down' something specific in writing or electronically.

• Фотограф зафиксировал на пленке момент взрыва.

  The photographer captured the moment of the explosion on film.

  This sentence uses "зафиксировать" to refer to 'capturing an image or event' using a device such as a camera.

• Врач зафиксировал нерегулярное сердцебиение пациента.

  The doctor identified irregular heartbeats in the patient.

  In this example, "зафиксировать" denotes the act of 'detecting or noting' a condition or occurrence, often in the context of observation or monitoring.