instrument for measuring the rise or drop in elevation of a liquid (as water in a reservoir) from a previously recorded level by means of a pointed hook that is directly connected to a fixed part containing a scale (as a vernier) and is submerged and moved gradually until its point just pierces the surface of the liquid from beneath when the measurement is taken, mõõtevahend, millega mõõdetakse vedeliku (veehoidlas oleva vee) tõusu või langust eelnevalt registreeritud tasemest terava konksu abil, mis on otse ühendatud skaalat sisaldava fikseeritud osaga ning on vee all ja mida liigutatakse järk-järgult, kuni selle punkt lihtsalt läbistab mõõtmise ajal vedeliku pinna altpoolt
