- Density: 1,00 g/cm3 r- Solub. in water: (20 ºC): miscibler- Tariff number: 3822 00 00 00r- Applications: This reference material is intended for the calibration of pH meters and electrodes used for pH measurement or as a control sample for measuring the pH value.rrSPECIFICATIONSrpH at 20 ºC: 8,00rspecification range: 7,99 - 8,01runcertainty : ± 0,01rComposition per litre is 3,1 g Boric acid, 3,7 g Potassium chloride and approx. 39,8 g Sodium hydroxide 0,1N. rrStandard buffer solutions are prepared using gravimetric and volumetric procedures. The batch value is determined by measurement with a combination glass electrode against five-point calibration according to DIN 19268. This pH buffer solution is traceable to Standard Reference Material from NIST. r0: 8,15r5: 8,10r10: 8,07r15: 8,04r20: 8,00r25: 7,96r30: 7,94r35: 7,92r40: 7,90r45: 7,87r50: 7,85r