Inoshandiswa kuyera kurasikirwa kwemvura kwezvisina kurukwa. Yakayerwa isina kurukwa, isa muenzaniso wakakombama mundiro yakatsveyama, ichiyera kana huwandu hweweti yekugadzira huchiyerera huchienda kumuenzaniso wakabatanidzwa, mvura kuburikidza nepakati pezvisina kurukwa inonyudzwa nekunyudzwa kwakajairwa, inonyudzwa nekuyera kuchinja kwehuremu hwepakati usati waedzwa uye mushure mekuyedzwa kwekushanda kwemvura isina kurukwa.
Edana152.0-99;ISO9073-11.
1. Bhenji rekuyedza rakaiswa mitsetse miviri mitema, daro riri pakati payo riri 250±0.2mm;
Mutsetse wakaderera, 3±0.2mm kubva kumagumo ebhenji rekuyedza, ndiyo nzvimbo yenzvimbo yekunyudza mvura kumagumo;
Mutsetse wepamusoro ndiwo mutsetse wepakati pechubhu yekudhonza mvura inenge 25mm pasi kubva pamusoro pemuenzaniso wekuyedza.
2. Kurerekera kwepuratifomu yekuedza madhigirii makumi maviri nemashanu;
3. Chigadziko: kana mudziyo wakafanana (unoshandiswa kugadzirisa nzvimbo yepakati pemuenzaniso) unogona kugadzirisa muenzaniso panzvimbo ye (140 s 0.2) mm yakaenzana nemutsetse wekutarisa.
4. Nzvimbo yepakati (kuona kuti mvura iri kuburitswa muchubhu);
5. Furemu yekutsigira ine padhi rekushandisa mvura pamucheto wakaderera wemuenzaniso wekuyedza;
6. Chubhu yegirazi: dhayamita yemukati i5mm;
7. Hwaro hwemhete;
8 Mudziyo wekudonhedza: kani mu (4±0.1) s muchimiro chemvura (25±0.5) g yekuyedza mvura kuburikidza nechubhu yekuyedza yegirazi;