Apera Instruments 201DJ-C User manual

201DJ-C Double-Junction pH Electrode
User Manual

Brief Introduction
Apera Instruments 201DJ-C Double-Junction pH Electrode is featured with a proprietary lithium glass
membrane for fast and stable readings and a double-junction structure to minimize the chance of a
clogged junction. The gel inner reference solution does not need to be refilled. This electrode is designed
for testing in complex water solutions such as wastewater and pool water as well as general water
solutions. The electrode may not work well in the following situations:
1. Long-term testing in high temperature solutions (>122°F or 60°C)
2. Frequent testing in strong alkaline (>12 pH) or acid (<2) solutions
3. Testing low ionic strength solutions like distilled or deionized water
4. Testing caustic solutions that will erode the polycarbonate housing of the electrode
Technical Specifications
Range
0 to 14 pH
Housing
Polycarbonate
Junction
Double-junction
Reference electrode
Ag/AgCl
Reference solution
Gel KCL
Connector
BNC
Cable length
3 Ft
Dimension
ø12*160 mm
Temperature sensor
N/A
Operating temperature
32 to 176°F (0 - 80°C)
How to Install the Electrode
1. Find the BNC socket (where it shows pH ORP) on the pH meter; Open the rubber cap; Insert the
blue BNC connector of the electrode to the BNC socket while twisting clockwise until it’s locked.

2. After installing the new electrode to your meter, a 3-point calibration must be performed to ensure
the accuracy.
How to Use the Electrode
1. There is a proper amount of storage solution in the cap on top of the electrode. The pH glass sensor
tip is soaked in it to keep its sensitivity.
2. Before measuring, loosen the bottle cap, then pull out the electrode while twisting
counterclockwise. Place the storage bottle at a safe position.
3. Rinse the electrode with purified water and shake off excess water or blot-dry it with clean tissue
or filter paper. Never rub the glass membrane.
4. Insert the electrode into your sample solution and stir it for a few seconds in the solution to remove
potential air bubbles, which may cause unstable readings. Then wait for the stable reading and take
the measurement.
5. After use, insert the electrode while twisting clockwise into the storage bottle, then tighten the
bottle cap. If the KCL storage solution (SKU: AI1107) in the cap is contaminated, please fill in
new storage solution (other brands’storage solution may not work with this electrode).
How to Maintain the Electrode
1. Always rinse the glass bulb sensor on top of the electrode with purified water (distilled or deionized
water) before and after each test and calibration. For general contaminants stuck on the glass bulb
sensor, use warm soap water and a soft brush to clean off; For special contaminants, please refer
to the following table for proper cleaning solutions:
Contaminant
Cleaning Solutions
Inorganic metal oxide
Dilute acid less than 1mol/L
Organic lipid
Dilute detergent (weak alkaline)
Resin macromolecule
Dilute alcohol, acetone, ether
Proteinic haematocyte sediment
Acidic enzymatic solution (saccharated yeast tablets)
Paints
Dilute bleacher, peroxide

2. Make sure the glass bulb sensor is covered by the KCL storage solution (SKU: AI1107) in the
storage cap when not in use.
3. Never store pH electrodes in pure water like RO water, tap water, distilled water, or deionized
water as they will cause damage to the electrode.
4. Keep the electrode connector clean and dry. Use cotton balls with isopropyl alcohol to clean if it
gets dirty and then blow-dry it. This is to prevent a potential short circuit, which will undermine
the electrode’s performance.
5. pH electrodes do not last forever. They age through normal use and eventually will fail. The regular
service life of the pH electrode is 1-2 years. If you feel like the response of your pH electrode is
much slower, or the slope is lower than 90% (most Apera portable/benchtop pH meters will show
the slope data between every two points of calibration), it’s time to replace with a new electrode
to ensure accuracy.
Limited Warranty
We warrant this electrode to be free from defects in material and workmanship and agree to repair or
replace free of charge, at the option of APERA INSTRUMENTS, LLC, any malfunctioned or damaged
product attributable to responsibility of APERA INSTRUMENTS, LLC for a period of SIX MONTHS
from the delivery.
This warranty does not cover any damages due to:
Accidental damage, transportation, storage, improper use, failure to follow the product instructions,
unauthorized repair, normal wear and tear, or any other actions or events beyond our reasonable control.
APERA INSTRUMENTS, LLC
Address: 6656 Busch Blvd, Columbus, OH 43229 Phone: [phone]
Website: aperainst.com Email: [e-mail]