6554 pH/ORP Sensor

6-Series Legacy Sondes

View YSI 6-Series water quality sondes being used in a variety of water environments for long-term underwater monitoring and spot sampling.

PriceRequest Pricing


Simple, accurate pH/ORP measurement in sensors designed for minimal maintenance in sampling, profiling, and long-term monitoring applications.

This sensor must be installed into a 600R and 600QS sondes to function. Does not function on its own.

  • Overview

    YSI pH and pH/ORP sensors have been carefully designed to perform under all ionic strength conditions, from seawater with a conductivity of 53,000 μS/cm, to "average" freshwater lakes and rivers with conductivities of 200 to 1500 μS/cm, to pure mountain streams with conductivities as low as 15 μS/cm, which has historically been the most difficult medium with respect to accuracy, quick response to pH changes, and minimal flow dependence.

    ORP is determined by measuring the potential of a chemically-inert (platinum) electrode which is immersed in the solution. The sensing electrode potential is read relative to the reference electrode of the pH probe and the value is presented in millivolts.

    6554 pH Sensor:
    The YSI 6554 is a replacement pH sensor for use with YSI 600R and 600QS multi-parameter water quality. 65581 pH Probe and 6580 pH Reference also available.

    This sensor requires service center installation – contact us to schedule your sonde for servicing.

    Sensor is installed on the following sondes: 

    • 600R and 600QS
    • Only the 6580 pH reference is user-replaceable

    General Specifications:
    Range: 0 to 14 units
    Resolution: 0.01 unit
    Accuracy: ±0.2 unit

    U.S. EPA ETV

  • Specifications
    Depth / Pressure Rating / Limit 60 m
    Equipment used with 600R, 600QS
    Medium Fresh and Salt Water
    Monitoring Yes
    Parameters Measured pH, ORP
    Sampling Yes
    User Calibratable Yes
    User Replaceable Yes
    Warranty 1 year

You may also need

pH Buffer

pH Buffer


Zobell Solution, ORP Calibrator

Zobell Solution, ORP Calibrator

$41.75 - $93.75

EXO pH & ORP Smart Sensor

EXO pH & ORP Digital Smart Sensor (Unguarded)

Request Pricing

EXO2 Multiparameter Sonde

Multiparameter Water Quality Sonde for Unattended Monitoring (7 sensor ports, including a central wiper port)

Request Pricing

EXO pH Smart Sensor

EXO pH Digital Smart Sensor (Unguarded)

Request Pricing