YSI 3161 [065270] Conductivity Standard, 1,000 uS, 1 quart. NIST-traceable conductivity solutions to calibrate both field instruments and lab instruments and cells together for maximum accuracy. To ensure quality, YSI inspects conductivity solutions with reference to primary standard solutions according to OIML recommendation 56. Bottles include a table of corrections at temperatures between 20 and 30 oC.