YSI ProDSS pH Sensors
Features
- 0 to 14 unit measurement range
- T63<3 sec response time
- ±0.2 pH unit accuracy within ±10˚C of calibration temp
- Free ground shipping
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
The YSI ProDSS pH and pH/ORP sensors are digital smart sensors featuring welded titanium construction for use with the ProDIGITAL family of instruments. Compatible instruments include the ProDSS Meter, ProSwap Meter, and ProSwap Logger. Users can choose between a pH sensor or a combination pH/ORP sensor to measure these parameters. pH describes the acid and base characteristics of water. A pH of 7.0 is neutral; values below 7 are acidic; values above 7 are alkaline. ORP designates the oxidizing-reducing potential of a water sample and is useful for water which contains a high concentration of redox-active species, such as the salts of many metals and strong oxidizing (chlorine) and reducing (sulfite ion) agents. However, ORP is a non-specific measurement—the measured potential is reflective of a combination of the effects of all the dissolved species in the medium. Users should be careful not to overinterpret ORP data unless specific information about the site is known.
Replaceable Sensor Module
The ProDSS pH and pH/ORP sensors have a unique design that incorporates a user-replaceable sensor tip (module) and a reusable sensor base that houses the processing electronics, memory, and wet-mate connector. This allows users to reduce the costs associated with pH and pH/ORP sensors by only replacing the relatively inexpensive module periodically and not the more costly base.
Electrodes
ProDSS measures pH with two electrodes combined in the same probe: one for hydrogen ions and one as a reference. The sensor is a glass bulb filled with a solution of stable pH (usually 7) and the inside of the glass surface experiences constant binding of H+ ions. The outside of the bulb is exposed to the sample, where the concentration of hydrogen ions varies. The resulting differential creates a potential read by the meter versus the stable potential of the reference.
The ORP of the media is measured by the difference in potential between an electrode which is relatively chemically inert and a reference electrode. The ORP sensor consists of a platinum button found on the tip of the probe. The potential associated with this metal is read versus the Ag/AgCl reference electrode of the combination sensor that utilizes gelled electrolyte. ORP values are presented in millivolts and are not compensated for temperature.
Signal Quality
Signal conditioning electronics within the pH sensor module improve response, increase stability, and reduce proximal interference during calibration. Amplification (buffering) in the sensor head is used to eliminate any issue of humidity in the front-end circuitry and reduce noise.
ProDSS Smart Sensor Specifications:
| Parameter |
Range | Accuracy* | Resolution |
|---|---|---|---|
|
Conductivity |
0 to 200 mS/cm |
From 100 to 200 mS/cm: ± 1% |
**0.001, 0.01 or 0.1 µS/cm |
|
Temperature |
-5 to 70 °C |
± 0.2 °C |
0.1 °C or 0.1 °F |
| Dissolved Oxygen |
0 to 50 mg/L |
From 0 to 20 mg/L: ± 1% From 20 to 50 mg/L: ± 8% |
0.01 mg/L or 0.1 mg/L |
| pH |
0 to 14 |
± 0.2 |
0.01 |
|
ORP |
-1999 to 1999 mV |
± 20 mV |
0.1 mV |
| Turbidity |
0 to 4000 FNU |
From 0 to 999 FNU: ± 2% From 1000 to 4000 FNU: ± 5% |
0.1 FNU |
| Freshwater Total Algae |
0 to 100 µg/L PC |
r2 = 0.999 |
0.01 µg/L PC |
| Saltwater Total Algae |
0 to 280 µg/L PE |
r2 = 0.999 |
0.01 µg/L PE |
| Nitrate |
0 to 200 mg/L |
± 10% |
0.01 mg/L |
| Ammonium |
0 to 200 mg/L |
± 10% |
0.01 mg/L |
| Chloride |
0 to 1000 mg/L Cl |
± 15% |
0.01 mg/L |
*Reference specification for each sensor for more details on accuracy
** Range dependent
Select Options
In The News
Cal Poly, San Luis Obispo Manages Monitoring Efforts in Morro Bay
California Polytechnic State University, San Luis Obispo (Cal Poly, SLO), has been monitoring Morro Bay for decades, and while the monitoring program has changed over the years, the dedication to monitoring the bay has remained the same. The project started in 2006 as a Packard Foundation-funded initiative to monitor water quality flowing in and out of Morro Bay. The goal at the time was to use the data collected to develop and inform an ecosystem-based management plan in collaboration with the Morro Bay National Estuary Program (MBNEP). Since the estuary was the focus at the time, researchers were monitoring water flowing into the estuary from Chorro Creek and Los Osos Creek.
Read More
Green Water in Green Bay: Using Data Buoys to Monitor the Southern Bay
While the bay of Green Bay has been referred to as the largest freshwater “estuary” in the world, the watershed hosts intensive agriculture and contributes one-third of Lake Michigan’s total phosphorus load. The Fox River flows into the bay, carrying excess nutrients largely the result of non-point source runoff from the watershed. With a history of deterioration extending well into the last century, the bay ecosystem suffered significant declines in water quality. This, in turn, stimulated major clean-up and ongoing restoration efforts to improve water quality. Tracking these changes is an important aspect of ecosystem management.
Read More
Cross-Border Sewage Contaminated Flows: Monitoring the Tijuana River
The Tijuana River runs across the US-Mexico boundary, flowing into and throughout southern California, carrying with it nutrients and contaminants throughout the estuary. In recent decades, the flows have been heavily polluted with untreated sewage from the City of Tijuana. The wastewater enters the greater Tijuana River estuary, impacting coastal communities and disrupting the natural environment. In order to better understand these cross-border flows, researchers out of San Diego University sought to monitor the waterway test the capabilities of in-situ sensors to measure the contaminated water. Natalie Mladenov and Trent Biggs were two of the researchers involved in the project, deploying a real-time monitoring system in May of 2021.
Read More
