Handheld Water Analyzers: Which Parameter, Which Instrument?
Pyxis handheld measuring instruments for chlorine, pH, ORP, conductivity, turbidity, fluorescent tracers, and reagent-based tests.
Instrument by Parameter
Selecting a handheld water analyzer starts with the parameter you will measure:
- Free / total chlorine: SP-208 OXIGO (pocket type, low 0.02–2.2 and high 0.1–10 ppm ranges); SP-505 and SP-600 (chlorine + pH, ORP, conductivity).
- pH, ORP, conductivity, TDS, turbidity: SP-505 (including turbidity, conductivity 1–15,000 µS/cm); SP-600 (conductivity 1–200,000 µS/cm, TDS, resistivity); SP-710B (pH, ORP, conductivity, PTSA).
- Cooling and boiler water tracers and inhibitors: SP-350, SP-350RO, SP-380, SP-395, SP-395T, SP-395N, SP-400 fluorometers.
- Multiple reagent-based tests: SP-800 (more than 65 methods, turbidity 0–200 NTU) and SP-910 (7-LED colorimeter for tests such as chlorine, phosphate, iron, and copper, plus PTSA, fluorescein, and turbidity).
- Bleach concentration: SP-210 (reagent-free, 0.01–16%).
- Algae (chlorophyll-a): EM-400. Details: chlorophyll sensors.
Pyxis Handheld Instruments
Values are taken from Pyxis datasheets and user manuals. All instruments connect to the uPyxis app via Bluetooth 5.0.
| Instrument | Measured parameter | Measuring range | Method | Details |
|---|---|---|---|---|
| SP-350 | PTSA tracer | 0–300 ppb | UV fluorescence | Cooling and process water |
| SP-350RO | PTSA tracer | 0–40 ppb | UV fluorescence | Reverse osmosis feed water |
| SP-380 | PTSA + fluorescein | PTSA 0–300 ppb; fluorescein 0–600 ppb | UV fluorescence | Cooling, process, and boiler water |
| SP-395 | Halogen-resistant azole | 0–7.5 ppm | Fluorometer (SP-300/400 family) | Halogen-resistant azole inhibitor |
| SP-395T | Tolyltriazole (TTA) | 0–10.0 ppm | UV absorbance | No acidification required; color and turbidity compensation |
| SP-395N | NDSA tracer | 0–100 ppb | UV fluorescence | Research and boiler water; false low readings may occur in the presence of nitrite |
| SP-400 | PTSA + conductivity | PTSA 0–300 ppb; conductivity 0–15,000 µS/cm | UV fluorescence + conductivity | Tracer and blowdown tracking in cooling water |
| SP-505 | pH, ORP, conductivity, turbidity, free/total chlorine, temperature | pH 0–14; ORP -1500…+1500 mV; conductivity 1–15,000 µS/cm; turbidity 0–100 NTU; chlorine 0.00–10.00 ppm; temperature 0–70 °C | Electrochemical, nephelometric (ISO 7027), DPD | Replaceable Bluetooth pH/ORP module; 8 GB storage |
| SP-600 | Conductivity, TDS, resistivity, pH, ORP, free/total chlorine, temperature | Conductivity 1–200,000 µS/cm; resistivity 10–30 MΩ; pH 0–14; ORP -1500…+1500 mV; chlorine 0.00–10.00 ppm | Electrochemical, DPD | No turbidity channel; default TDS factor 0.67 |
| SP-800 | More than 65 reagent tests; turbidity | Turbidity 0–200 NTU; 7 LED wavelengths (365–630 nm) | Colorimetry, white light/IR turbidity | 10 mL and 25 mL vials; COD vial adapter |
| SP-208 OXIGO | Free or total chlorine | 0.02–2.2 ppm (low); 0.1–10 ppm (high) | DPD colorimetry | Pocket type; 30,000 data groups; compliant with EPA 334.0 DPD guidelines |
| SP-210 | Sodium hypochlorite (bleach) | 0.01–16% w/w (as Cl2) | Reagent-free UV absorbance (365/395 nm) | Temperature-compensated; incoming shipment inspection and quality control |
| SP-710B | pH, ORP, conductivity, PTSA, fluorescein, temperature | PTSA 0–300 ppb; fluorescein 0–600 ppb; conductivity 1–15,000 µS/cm; pH 0–14; ORP -1500…+1500 mV | Electrochemical and fluorescence | Cuvetteless; replaceable pH/ORP module |
| SP-910 | PTSA, fluorescein, turbidity, reagent tests (chlorine, phosphate, iron, copper, etc.) | PTSA 0–300 ppb; fluorescein 0–600 ppb; turbidity 0–200 NTU | 7-LED colorimeter (365–630 nm), fluorescence, white light/IR nephelometer | Combined photometer and fluorometer; new methods can be added via the app |
| EM-400 | Chlorophyll-a (in-vivo) | 0–50 ppb | Fluorescence (470/650 nm) | Algae monitoring; stable reading in 5 seconds |
Three Measurement Methods: Electrochemical, Colorimetric, Fluorescence
Electrochemical
pH, ORP, and conductivity are measured with electrodes and cells. The pH/ORP module on SP-505 and SP-600 communicates with the main body via Bluetooth and can be replaced in the field without disassembly; typical module life is 18 months, while typical life for the conductivity, turbidity, and chlorine sections on SP-505 is 5 years, and 5 years for conductivity on SP-600. Conductivity and pH feature automatic temperature compensation.
Colorimetric (reagent-based)
A powder reagent pillow such as DPD is added to the sample, and the resulting color is measured by the instrument's LED and detector. SP-208 and SP-505/SP-600 use DPD for free and total chlorine; the list of more than 65 methods on SP-800 covers tests such as alkalinity (5–100 and 100–500 ppm), calcium hardness (25–500 ppm), chloride, free/total chlorine (0.02–2.20 and 0.1–10.0 ppm), chlorine dioxide (0.04–5.0 ppm), copper, iron, nitrate, nitrite, ammonia, fluoride, hydrogen peroxide, ozone, color, and COD (15–150 and 100–1500 ppm).
Fluorescence and UV
The SP-300/400 family excites the tracer chemical (PTSA, fluorescein, NDSA) around 365 nm and measures its fluorescence, while SP-395T and SP-210 use UV absorbance. Color and turbidity compensation is performed by an internal algorithm; if turbidity is excessive, an over-turbidity alarm is triggered.
Which Instrument for Which Facility?
Cooling tower and boiler
SP-350, SP-380, or SP-400 (including conductivity/blowdown) for verifying chemical dosing via PTSA tracer; SP-395T and SP-395 for azole inhibitors; SP-505 (pH, ORP, conductivity, turbidity, chlorine) for multi-parameter field audits. Related: cooling tower automation.
Reverse osmosis feed water
SP-350RO (0–40 ppb) for low-level verification of antiscalant tracer in reverse osmosis feed lines.
Drinking water and disinfection lines
SP-208 OXIGO or SP-505/SP-600 for field verification of free and total chlorine residual, as well as calibration checks of online analyzers. In incoming bleach shipment inspection, SP-210 delivers results without reagents.
Laboratory and municipal, environmental, and industrial water analysis
SP-800 is a multi-method instrument that also measures turbidity, carrying methods aligned with APHA/USEPA/ISO guidelines alongside Pyxis direct-read methods; SP-910 adds PTSA and fluorescein fluorescence to the same 7-LED colorimeter platform.
Related pages: Pyxis handheld and inline instruments · Online analyzers
Frequently Asked Questions About Handheld Water Analyzers
Instrument selection, test kit comparison, chlorine measurement, cuvettes, protection rating, and data transfer.
How do I select a handheld water analyzer?
First identify the parameter you will measure. For free and total chlorine, SP-208 OXIGO (pocket type) or SP-505/SP-600; for pH, ORP, conductivity, and turbidity, SP-505, and for conductivity and TDS, SP-600; for multiple reagent-based tests (alkalinity, calcium, iron, COD, nitrate, etc.), SP-800; for fluorescent tracers and inhibitors (PTSA, TTA, NDSA) in cooling and boiler water, the SP-350, SP-380, SP-395, and SP-400 series; for bleach concentration, SP-210; and for chlorophyll-a, EM-400 are appropriate.
What is the difference between a test kit and a handheld colorimeter?
In both, a reagent is added to the sample and the resulting color is evaluated. In a handheld colorimeter (SP-208, SP-800), the color is measured by the instrument's LED light source and detector, and the result is read on the screen in ppm; a live concentration-versus-time curve is displayed during the test. Results are transferred via Bluetooth to the uPyxis app for record-keeping.
Which instrument is suitable for chlorine measurement?
SP-208 OXIGO offers two ranges for free or total chlorine: a low range of 0.02–2.2 ppm and a high range of 0.1–10 ppm, operating with the DPD method and in accordance with EPA 334.0 DPD test guidelines. SP-505 and SP-600 combine 0.00–10.00 ppm DPD chlorine measurement with pH, ORP, and conductivity in the same body. For online analyzers, see our online analyzers page.
Is a sample cuvette required?
In the SP-350, SP-380, SP-395, SP-400, SP-210, and EM-400 family, the sample is poured directly into the instrument's sample cell — no cuvette is required. SP-208 and SP-800 use 10 mL (MA-24) or 25 mL (MA-25, SP-800) sample vials in reagent-based tests; SP-800 also comes with a 16 mm COD vial adapter.
Are the instruments waterproof and field-rugged?
According to the datasheets, SP-208, SP-210, the SP-350/380/395/400 fluorometers, SP-505, SP-600, and SP-800 are rated IP67 (dustproof and waterproof). The displays are readable in direct sunlight. The operating sample temperature for the chlorine colorimeters and fluorometers is 4–41 °C.
How are data logged and transferred?
All Pyxis handheld instruments include Bluetooth 5.0 and use the uPyxis mobile or desktop app for configuration, data transfer, and firmware updates. SP-505 and SP-600 store 8 GB of timestamped logs, while SP-208 and SP-210 store 30,000 data groups.
Does a handheld instrument replace an online sensor?
No — they complement each other. An online sensor measures continuously and sends a signal to a controller, whereas a handheld instrument is intended for spot verification, periodic audits, and cross-checking inline sensors. Pyxis SP-300/400 series fluorometers are designed for direct correlation with Pyxis inline fluorometers measuring the same tracer.
Send the make and model of your current instrument to [email protected] — our engineers will propose the equivalent with the same connection and measuring range.
Planning a project? Send us your flow rate, feed water source and target water quality to [email protected] — our engineers will reply with a technical proposal.