Salinity Standard Solution 36ppk

It is the accepted working value for full-strength seawater, so it calibrates a meter right at the point marine systems actually operate.

Yes — the product title uses the house spelling ppk, and the standard is 36 parts per thousand, also written 36 PSU.

The reference temperature is not published by the supplier — check the bottle label, and let the standard reach room temperature before you calibrate.

Yes — it makes a good single-point check on a handheld refractometer, which drifts with knocks and temperature.

Handheld salinity meters and conductivity-based probes including the YSI Pro30 and YSI EC300A, plus inline marine sensors.

No — diluting introduces error; use a conductivity standard at the value closest to your brackish working range instead.

Sealed, out of direct sun and at stable room temperature — evaporation from an open bottle raises the true salinity and will bias every calibration.