Bluelab Calibration Solution 500 mL | 2.77 EC / 27.7 CF Conductivity Standard

Why Bluelab Calibration Solution Comes in 500 mL

Nothing about the fluid changes with the bottle. It is the same 2.77 EC standard, the same 27.7 CF, certified to NIST and made by Bluelab for its own meters. What changes is how fast you get through it. The rule that a probe never enters the bottle is what drives the volume. Every check means pouring a fresh sample into a separate container, using it once, and tipping it away. Do that weekly with one pen and a small bottle is plenty. Do it weekly across a pen, a Truncheon and a Guardian, and the pours add up. 500 mL is the size for a bench with more than one instrument on it. It also costs less per millilitre, which is the usual reason people move up.

Using a Conductivity Standard Solution on a Monitor

On a monitor the job differs a little from a pen. A Guardian sits in the tank permanently, so its probe collects film rather than drying out. The standard is what tells you whether that film has started to matter. Clean the probe, rinse it in fresh water, then read it in a poured sample. A reading that sits on 2.77 means the probe is reporting honestly, and the number on the wall is the real one. A reading that will not settle is almost always a cleaning problem rather than a calibration problem. Store the bottle sealed and cool with the lid tight, out of direct sun. Heat and light are what age a standard on a shelf.

Key Features

• Same fluid, larger bottle: Identical 2.77 EC standard to the 250 mL, NIST certified and traceable.
• Sized for several meters: A pen, a Truncheon and a Guardian on one bench get through it quickly.
• Lower cost per millilitre: The usual reason to step up once more than one instrument is in use.
• Every check is a fresh pour: Used solution is discarded, so volume disappears faster than people expect.
• Never dip into the bottle: One probe in the bottle compromises the reference for every check after it.
• Reads the film on a monitor: A permanently submerged Guardian probe collects film rather than drying.
• Clean before you calibrate: A reading that will not settle is usually dirt, not a lost calibration.
• Store sealed and cool: Heat and direct light are what shorten the life of a standard on a shelf.
• Keep away from children: Standard solution is a chemical reference, not something to leave out.

Technical Specifications