kaminahi kirjutas:aga ma kas saan millestki valesti äkki aru, aga eksamikomisjoni liige ei saa ometi kinnitada, et vaid just HBO+ on sobilik ja seda seepärast, et nii seal standardis ju kohe ikka tõesti ei ole.
Aga loeme siis, mis standardis on:
"This standard is valid for ...(tiled/mortared stoves) equipped with fireclay as interior material ..."
Hea küll - "fireclay" on Wikipedia andmetel väga mitmekesine materjal:
"Fire clay is a term applied to a range of refractory (heat resistant) clays used in the manufacture of ceramics, especially fire brick.
High grade fire clays can withstand temperatures of 1775°C (3227°F, PCE 35), but to be referred to as a "fire clay" the material must withstand a minimum temperature of 1515°C (2759°F, PCE 19).[1] Fire clays range from flint clays (non-plastic) to plastic fire clays, but there are semi-flint and semi-plastic fire clays as well. Fire clays consist of natural argillaceous materials, mostly Kaolinite group clays, along with fine-grained micas and quartz, and may also contain organic matter and sulphur compounds."
http://en.wikipedia.org/wiki/Fire_clay
"...with an apparent density between 1.750 kg/m3 and 2200 kg/m3..."
selge, siin on tiheduse piirid ette antud
"...a degree of porosity from 18% to 33% by volume ..."
ka siin on selge, need on poorsuse mahuprotsendid
"and a heat conductivity from 0.65 W/mk up to 0.90 W/mK (temperature range 20C to 400C)."
ja sellega on ka soojusjuhtiivuse piirid ära öeldud.
Mitte sõnagi ei leia ma standardist spetsiifilise materjali kohta, mida Andrus siin "kergšamotina" siin välja reklaamib.
Mitte sõnagi ei leia ma standardist ühegi firma konreetse toote kohta.
Mitte sõnagi ei leia ma standardist üldmaterjalist ("fireclay") erineva koldematerjali kohta - kuid ega siis kogu ahju šamotist laota?
Nii et kutseeksami jaoks peaks lihtsalt teadma materjale, mis antud standardi eelmainitud nõuete piiridesse mahuvad - nendest on siis ka võimalik antud standardile vastav ahi kavandada.