Maendlelo yo Pima Ndzhongo Emisaveni

Hi Xikongomelo aku Endla Minkarhi yo Cheleta

©Louise Brodie
Tensiometer dial.
Swina nkoka swinene kutiva xiyimo xa ndzhongo emisaveni leswaku mubyari ata cheleta swibyariwa hinkarhi lowufaneleke ku tiyisisa leswaku kuna ndzhongo lowu lavekaka emisaveni leswaku timintsu ta ximilani tita kota ku tswonga kona. Ku pima misava xikan’we naku tiyisisa leswaku swimilani aswivi ehansi ka ntshikelelo kutani kuva naku lahlekeriwa eka vuhumelerisi hikwalaho ka mpfumaleko wa mati eka misava leswaku swimilani swita kula kahle, tindlela tohamba hambana xikan’we na switirhisiwa swohambana hambana swa tirhisiwa leswaku swita languta ndzhongo emisaveni naswona leswitalaka ku tirhisiwa eka ku kunguhata kucheleta hi leswi:
The Neutron Probe Meter
Gypsum block
Tensiometer kumbe irrometer
Kuringeta na maendlelo lawa ya vonakaka
Time Domain Reflectometry (TDR) Probe

The Neutron Probe Meter

Neutron Probe Meter yi pima ndzhongo eka misava hikuva yihangalasa ti neutrons eka misava leyinga ekusuhi. Xitirhisiwa lexi xina leswi hinge i probe emakumu ka ntambhu leyiyaka eka meter box ya mpimo. Probe yina ti neutron leti hatlisaka swinene, letingavaka nkatsakanyo wa radium na beryllium kumbe Americium na beryllium.
Ti Aluminium access tubes ta 500 mm kuya eka 1 000 mm hiku leha naswona ti 32 mm hiku anama titlhela tipfaleka laha tshakwini leti vekiwaka emasin’wini kuva ti teka tinhlayo ta ndzhongo emisaveni. Eka swimilani leswi timintsu takona tinga entangiki xikan’we nati annuals, ti tubes to koma tinga tirhisiwa ematshan’weni ya letiya titirhisiwaka eka timintsu letinga enta kumbe swimilani leswi hanyaka malembe lawa yotala.

Ti neutron probe tinghenisiwa eka ti access tube kuya fikelela eka vuenti lebyi lavekaka kutani ti neutrons leti hatlisaka ta humesiwa kuya eka probe. Kutani ti neutrons tihangalaka tinghena emisaveni. Loko ti neutrons leti tihlangana na mati, rivilo rati neutrons rihunguteka kutani mitara yi hlayela nhlayo yati neutrons leti nonokaka. Nhlayo yati neutrons letinga hunguteka rivilo yi ringana nati molecules ta mati eka misava leyinga kwala kusuhi. Hiku tisa vuxokoxoko lebyi eka software, nhlayo ya vukona bya ndzhongo emisaveni yitiveka kusuka eka calibration curve leyi kombaka nhlayo yati neutrons letinga hunguteka rivilo.
Swakahle
Mimpimo ya hatlisa naswona yiya emahlweni. Kutirhisiwa ka Neutron Probe aswi lavi leswaku misava yikavanyetiwa naswona yinga pima ndzhawu yikulu (200 mm kuya eka 400 mm kusuka laha kungana ti probe tubes) kutlula maendlelo yanwana.
Swoka swingari kahle
Kutirhisa Neutron Probe swa durha, switirhisa ti radioactive naswona swilava kutshama swirikarhi swilulamisiwa hi mutirhi loyi angina ntokoto. Kukuma nhlayo ya mampela ya nhlayo ya ndzhongo eka misava leyi timintso tinga entangiki switala kuva xiphiqo hikuva ti neutrons ta rivilo tinga nonokisiwa hi ti hydrogen atoms tin’wana xikan’we nati atoms tati trace elements leti hi xitalo tikumekaka eka misava yale henhla ya 200 mm. Leswi swihetelela swi endla leswaku kuva naku ehleketeleriwa ka ndzhongo eka misava.

Gypsum, Vumba Kumbe ku Phamiwa ka Switina

Ti unit leti ta xivumbeko xa rectangle kumbe swibokisani swikwalomu ka 550 mm hiku leha, 375 mm hiku anama xikan’we na 20 mm hiku bumbula. Gypsum, vumba kupbe ku phamiwa ka switina switirhisiwa eka ku pimiwa ka ndzhongo wa misava hikuva ku vekeriwa switina eka ndzhawu leyi kulavaka ku pimiwa eka yona xikan’we naku langutiwa. Ku akiwa pherhe yati electrodes letinga kwalomu ka 20 mm hiku hambana eka switina leswi.
Ndlela leyi ya mapimelo yitirha hiku tirhisa gezi. Loko gezi rihundza eka ti electrodes leti timbirhi, leswi gezi rifambisaka swona swiringana na ndzhongo eka xitina. Loko xitina xitsakama, loko kuhundza gezi rotala swihlamusela leswaku resistance yile hansi. Hi xitalo, ti electrodes tihlaya kwalomu ka 400 kuya eka 600 ohms ya resistance eka nsimu yaleyo naswona yiri eka 50 000 eka wilting point, laha hiloko ximilani se xitsandzeka ku tswonga mati kuva yitihanyisa. Tinhlayo titekiwa hi Wheatstone Bridge Bouycos biriji ra mati leringana ti dry cells.
Vekela ti gypsum block eka misava leyinga kavanyetiwangiki.
Swakahle
Gypsum blocks ati tshembeki ngopfu eka misava leyi tsakamaka.

Tensiometer/Irrometer

©Louise Brodie
Entire Tensiometer.
Tensiometer i xitirhisiwa lexipimaka tension leyi mati yanga khomisiwa xiswona hi misava. Yina, tani hile makumu, 8 cm porous ceramic kumbe khapu ya vumba leyinga khomana na protective metallic kumbe glass tube leyingana vacuum gauge ehenhla. Switirhisiwa leswi swi cheriwa hi mati yatala hile eka mbhovo lowungale henhla naswona yita khoma mati emakumu ka vumba. Kutani yi pfariwa hi vacuum gauge loko yivekiwa emisaveni.
Vekela tensiometer hiku boxa mbhovo wo anama naswona wu ente kuringanela kuva kuringana tube leyingata fikelela e timintswini ta ximilani. Aku fanelangi kuva na moya emakumu ka tube. Kufanele kuva leyi ringanelaka. Ndzhongo kusuka eka khapu wutava wukarhi wu tekeka loko misava leyinga yi rhandzela yisungula ku oma. Leswi swi endla leswaku kuva na vacuum eka tube leyi pimiwaka hi gauge. Loko ntlimbo lowu lavekaka wufikeleriwile, misava yifanele ku cheletiwa. Vacuum gauge yikombeta tension eka ndzhawu yin’we kambe yi hlaya kuya fika eka 0.85.
Swa kahle
Tensiometer yi olovile naswona yi vekeleka hiku olova naswona yi hlaya ndzhongo wa misava kuya hi mfanelo. Ya pfuna swinene leswaku kuta cheletiwa swimilani leswi lavaka ku cheletiwa loko ndzhongo wu hunguteka.
Swoka swingari kahle
Ku twa ka tensiometer swikwalomu ka ku fika eka 0.85 atmospheres loko ndzhongo wa misava lowunga kona wunga kwalomu ka atmosphere yin’we. Tensiometer yitlhela yinyika nhlayo yantiyiso eka misava ya sandy kutlula eka misava leyingana vumba swinene.

Ndlela yo Twala na Mavonakelo

Loko kurihava na maendlelo na yan’we eka lawa yanga vuriwa laha henhla, maendlelo yaku ehleketelela ndzhongo lowungakona wunga tirhisiwa tani hi ndlela yo hetelela laha kunga tekiwaka swikombiso swa misava kuya hi vuenti lebyi tsakeriwaka. Swikombiso leswi swa misava swi pfuviwa hi mavoko naswona yitwiwa himavoko kutani ku langutiwa xivumbeko xa yona leswi tekeriwaka enhlokweni. Hiku tirhisa maendlelo lawa, kutiva kahle ndzhongo lowunga emisaveni swinge tiveki.

Time Domain Reflectometry (TDR) Probes

©Louise Brodie
TDR moisture probe head.
TDR probes i maendlelo lawantshwa lawa tirhisiwaka eka kutiva leswaku kufanele ku cheletiwa rini. Maendlelo lawa ya pima nkarhi lowu switekaka wona kuva electrical pulse yi fambaka wona eka ku leha ka ti stainless steel rods leti nghenisiweke emisaveni.
TDR probes hixitalo titirhisiwa eka ti greenhouses naswona titisa tinhlayo ta ntiyiso. Hambi swiritano, lawa i maendlelo lawa ya durhaka swinene kuyitirhisa eka purasi lerikulu.

Translated by Ike Ngobeni