Water Quality Meters, pH Buffers & Solutions

Water quality meters for pH, conductivity, ORP, TDS, and salinity — handheld meters, electrodes, and buffer solutions used in process, environmental, and lab checks.

Common tools on this site

• pH meters — REED R3500 pH meter, R3510 long-stem pH meter, and R3525 pH/mV meter with temperature; replacement electrodes (R3500-ELECTRODE, R3525-ELECTRODE / R3525-ELECTRODE2) when OEM pairing is clear.
• Logging pH/ORP — REED R3000SD data logging pH/ORP meter with optional R3000SD-PH2 and R3000SD-ORP electrodes.
• Conductivity / TDS / salinity — REED R3530 conductivity/TDS/salinity meter and R3100SD data logging conductivity meter with R3100SD-PROBE when stocked.
• Buffers and care solutions — REED R1400 pH buffer kit, R1404 / R1407 / R1410 buffers, R1420 electrode storage solution, R1425 electrode cleaning solution, and R1430 conductivity solution.

Choosing a meter

• Match the parameter (pH, conductivity, ORP, TDS, salinity) to the sample.
• Electrodes and buffer solutions are consumables — keep matching kits in stock for field work.
• Logging / SD models help when you document multiple sample points or shifts.

Care and buffers

• Use color-coded buffers (4.01 / 7.00 / 10.00) and electrode storage/cleaning solutions on the OEM schedule.
• Certificates of Analysis for buffers are often available from the manufacturer upon request.

Related categories

Browse instrument accessories for cases and leads, and environmental meters for related field instruments.

Models in this category

Conductivity, TDS and salinity meters

• REED R3100SD Data Logging Conductivity/ TDS/Salinity Meter: measures conductivity, total dissolved solids (TDS) and salt levels in water.
• REED R3530 Conductivity/ TDS/Salinity Meter: measures conductivity, total dissolved solids (TDS) and salt levels in a liquid.

pH and ORP meters

• REED R3500 pH Meter: dual LCD displays temperature and pH measurements.
• REED R3510 Long Stem pH Meter
• REED R3525 pH/mV Meter with Temperature: measures pH and mV levels in liquids.

Accessories and replacement parts: REED R1400 pH Buffer Solutions Kit, REED R1404 pH Buffer, REED R1407 pH Buffer, REED R1410 pH Buffer, REED R1420 Electrode Storage Solution, REED R1425 Electrode Cleaning Solution, REED R1430 Conductivity Solution, REED R3000SD Data Logging pH/ORP Meter, REED R3000SD-ORP ORP Electrode For R3000SD & SD-230, REED R3000SD-PH2 pH Electrode For R3000SD & SD-230, REED R3100SD-PROBE Replacement Conductivity/Salinity/Tds Probe For R3100SD & SD-4307, REED R3500-ELECTRODE Replacement pH Electrode For R3500, REED R3525-ADP Power Adapter For R3525, REED R3525-ELECTRODE Replacement pH/mV Electrode For R3525, REED R3525-ELECTRODE2 Replacement ORP Electrode For R3525, REED R3530-AK Replacement Allen Key And Screws For R3530, REED R3530-ELECTRODE Replacement Conductivity/Tds/Salinity Meter Electrode For R3530.

Calibration

Eligible meters can ship with ISO/IEC 17025 accredited calibration. Buffer kits and electrodes are linked from meter pages where OEM pairing is documented.

Frequently asked questions

Which REED pH meter should I choose?

• REED R3500: handheld pH meter, 0.01 to 14.00 pH at ±0.02 pH, with temperature from 32 to 122°F.
• REED R3525: pH/mV meter with temperature, 0.00 to 14.00 pH at ±(0.01 pH + 1 dgt), −1999 to 2000 mV, and temperature from 32 to 230°F.
• REED R3000SD: data logging pH/ORP meter, 0.00 to 14.00 pH and −1999 to 1999 mV, with a sampling rate from 1 second to 8 h 59 min 59 s.
• REED R3510: long-stem pH meter with a 4.7" (119.4 mm) pH probe.

Which buffer solutions do I need to calibrate a pH meter?

REED supplies 4.01 pH (R1404), 7.00 pH (R1407) and 10.00 pH (R1410) buffer solutions, each specified at 25°C in 16.9 fl oz (500 ml) bottles. The R1400 is a buffer solution kit.

How should I store and clean pH and ORP electrodes?

REED makes the R1420 Electrode Storage Solution and the R1425 Electrode Cleaning Solution specifically for pH and ORP electrodes.

Which meter measures conductivity, TDS and salinity?

• REED R3530: conductivity 0 to 2000 μS and 2.00 to 20.00 mS at ±2% FS, plus TDS and salinity.
• REED R3100SD: data logging model; conductivity ranges of 200 μS/cm, 2 mS/cm, 20 mS/cm and 200 mS/cm, TDS to 200,000 ppm, and salinity from 0 to 12%.

To check readings, the R1430 Conductivity Standard Solution is 1413 μS at 20°C.

Can I measure ORP with the R3000SD?

Yes. The R3000SD-ORP electrode covers 0 to 1999 mV (double junction, Ag/AgCl, BNC connection). The R3000SD-PH2 pH electrode covers 0 to 13 pH. Both are listed for the R3000SD and SD-230 meters.