Description

The MA920B/1 probe is a Direct Stick Measurement probe for use with the MW101 or MW102 PRO pH meters.

Design Features

The Milwaukee MA920B/1 grade probe is designed for the pH analysis of semisolid foods such as processed meats, soft cheeses, soups, sauces, and sushi rice or any soil Growing media such as Coco Coir, Soil, Rockwool and other media.  It's tough (PVDF) body and toxic free electrolyte is perfect for food or growing media!

Top features include:

Open Junction

The open junction design reduces clogging from suspended solids and proteins found in food and dairy products or growing media for a more stable pH measurement and reduced maintenance.

Conical Glass Tip

The conical shaped tip design allows for penetration into solids, semi solids, and emulsions for the direct measurement of pH in a variety of food or growing media products.

PVDF Body

Polyvinylidene fluoride (PVDF) is a food grade plastic that is resistant to most chemicals and solvents used for disinfection in the food sector, including chlorine (bleach).  It is also a tough material designed to hold up extremely well in all kinds of growing media applications.

Use and Care

pH meters usually start performing poorly because of problems with the probe. The two parts of the pH probe that cause problems are the glass sensing bulb and the reference junction.

Sensing bulb

The glass bulb loses sensitivity with use and will eventually fail. This is true of all pH probes.

Reference junction

The reference junction is a small hole that allows the meter to compare the sample to a reference. The reading is generated based on the electrical difference between the sample and reference. If the junction hole gets clogged, the pH probe will no longer function.

You can extend the life of your pH electrode in the following ways.

Storage

The pH probe needs to be kept hydrated. Long periods of dry storage will damage the sensitivity of the probe. Allowing the probe to dry out may also result in the junction hole getting clogged.

Storing in pH probe storage solution or pH calibration buffers will help address both these issues. Do not store in tap water and DI water. This will damage the sensitivity of the probe.

The best way to store the probe is with the probe's cap filled with storage solution or calibration buffer and the cap tightened to prevent leakage. It is also recommended that to store the electrode upright to further reduce the potential for leakage.

Cleaning

Residue from the sample can impact the sensitivity of the sensing bulb and clog the junction. This is especially true if the sample has a lot of organic material. We recommend regularly soaking your electrode in cleaning solution.

Calibration

The pH sensing bulbs become less sensitive over time so make sure that you are calibrating reguarly to keep your PRO pH meter accurate. Also, calibrate after cleaning or a long period of storage.