Bluelab EC 2.77 calibration solution 500 ML

A 500 ml bottle of Bluelab reference solution at 2.77 mS/cm, for anyone with several probes or several measuring points.

How to test an EC probe properly

A test against reference solution is only worth something if you do it properly. Four things decide whether your result means anything, and all four get skipped regularly.

1. Rinse the probe with clean water and shake it dry. Nutrient solution left clinging to it dilutes or contaminates the reference you are measuring in. A few drops are enough to shift your result.
2. Pour a shallow pool into a clean pot. Never test in the bottle itself. Dip a probe into your stock once and the whole bottle is suspect.
3. Let the solution reach room temperature. Conductivity rises sharply with temperature. Your meter compensates for that, but the compensation works best when liquid and meter are not far apart.
4. Stir gently and wait for the value to settle. Movement brings fresh solution past the electrodes and speeds the reading up. Reading too early is the most common mistake.

If the result is off, do not assume a broken meter. Clean the electrodes first: salt build-up and biofilm are by far the most common cause, and a fouled sensor generally reads low. Then test again.

Technical Specifications:

• Value: 2.77 mS/cm (2770 µS/cm)
• Volume: 500 ml
• Brand: Bluelab
• Use: calibrating and testing EC probes

Frequently asked questions

When do I choose 500 ml over 250 ml?
When you will finish it within about a year. Several meters or several rooms justify this size; with one meter, 250 ml is usually enough.

How long does an opened bottle stay good?
Conductivity reference is less sensitive than pH buffer, but it does age. Note the opening date and work on about a year.

My meter reads consistently low.
That almost always points to build-up on the electrodes. Clean them and test again before doubting the meter.

Can I calibrate pH with this?
No. Those are two different measurements, each with its own reference.