Buffer solutions – working standards рН of 2nd category

INTENDED FOR
Reproducing and transmitting the activity index of hydrogen ions (pH) in aqueous solutions; verification and calibration of рН measuring instruments according to GOST 8.120-2014 of controlling the metrological characteristics when tested, and for type approval; error control of measurement procedures (MP) рН of liquid media.
Buffer solutions are aqueous solutions of chemicals. Solutions reproduce values of activity of hydrogen ions. Buffer solutions are contained in plastic bottles. The bottle is leakproof and has a screw cap with a protective ring. Buffer solutions have 9 modifications, that differ by concentration of chemicals and reproducible values.
Field of application
for verification and calibration of working measuring instruments in research institutions, analytical laboratories рН.

SPHERES OF APPLICATION
Healthcare metrological support,  food industry, laboratory research.

Limits of permissible absolute accuracy of рН reproduction: 

in the temperature range from + 5 to + 20°С ±0.02
in the temperature range from + 20 to + 40°С ±0.01
in the temperature range from + 40 to + 80°С ±0.02
Bottle volume 125 см3, 270 см3
Expiry date 1 year.

 

Marking of buffer solutions Marking of buffer solutions Chemical formula of substances Substance concentration рН reproducible value at temperature +25°С
BR-рН-1 Potassium tetraoxalate dihydrate KH3(C2O4)2·2H2O 0,1 1.48
BR-рН-2 Potassium tetraoxalate dihydrate KH3(C2O4)2·2H2O 0,05 1.65
BR-рН-3 Potassium hydrogenphthalate KНC8H4O4 0,05 4.01
BR-рН-4 Potassium phosphate monosubstituted
Sodium phosphate twice-substituted
KH2PO4
Na2HPO4
0,025
0,025
6.86
BR-рН-5 Potassium phosphate monosubstituted
Sodium phosphate twice-substituted
KH2PO4
Na2HPO4
0,0087
0,0304
7.41
BR-рН-6 Potassium phosphate monosubstituted
Sodium phosphate twice-substituted
Na2B4O7◦10H2O 0,01

0,04

7.43
BR-рН-7 Sodium tetraborate decahydrate Na2B4O7◦10H2O 0,01 9.18
BR-рН-8 Sodium tetraborate decahydrate Na2B4O7◦10H2O 0,05 9.18
BR-рН-9 Sodium carbonate
Sodium carbonate acid
Na2CO3
NaHCO3
0,025
0,025
10.00