Hanna Instruments HI-6421/P Advanced Dissolved Oxygen Polarographic Benchtop Meter
The HI-6421/P Advanced Benchtop Meter for Dissolved Oxygen provides a laboratory-grade solution for measuring DO, BOD, OUR and SOUR in fresh and saltwater samples with a polarographic DO probe. This modern, streamlined meter has five individual viewing modes and ethernet and WiFi connectivity for easy remote data transfer.
HI-6421/P Advanced Dissolved Oxygen Polarographic Benchtop Meter
The HI-6421/P polarographic DO meter is a highly accurate laboratory benchtop solution for measuring dissolved oxygen, biochemical oxygen demand, oxygen uptake rate and specific oxygen uptake rate in salt and freshwater samples. This meter is supplied with a polarographic probe, while the HI-6421 is supplied with an optical Opdo probe.
The Hanna HI-764833 polarographic probe is a slim and versatile option covering a wide range of dissolved oxygen. This probe has a platinum cathode with Ag/AgCl anode assembly, enabling a fast response time with readings that are not dependent on flow.
The HI-764833 also features a built-in thermistor temperature sensor, allowing for compensation with temperature variation. The slim shape and size of this DO probe make it suitable for use with test tubes and BOD bottles.
HI-6421 Laboratory DO Polarographic Meter Features
Practical, streamlined design
Every meter in the HI-6000 series is designed with modern laboratories in mind, with a compact footprint and minimalist design to allow for ease of operation and placement. A large, capacitive touchscreen makes it easy to set up and take measurements, while connectivity via WiFi and ethernet allows for flexibility in placement, with no requirement for proximity to a PC or printer.
Supplied with Hanna polarographic DO probe
The Hanna HI-764833, a slim test tube-compatible polarographic probe, is supplied with the HI-6421/P. This robust probe is designed for a wide range of applications and is fitted with durable (PTFE), oxygen-permeable, screw-on membrane caps. These caps are filled with electrolyte and easily installed on the probe.
Automatic compensation
The HI-6421/P automatically compensates for barometric pressure, temperature, and salinity. Temperature is automatically measured and compensated for, while salinity is compensated automatically once a salinity concentration of the water has been defined manually.
A built-in barometer allows pressure compensation to be automatic or manually entered depending on specific requirements, with a range of user-configurable units offered: mmHg, mbar, kPa, inHg, psi and atm.
Built-in methods and calculations
The Hanna HI-6421/P advanced DO meter also can act as an OUR, SOUR and BOD meter, with built-in methods and calculations included within the instrument to allow for accurate and reliable measurement of these parameters.
Flexible electrode holder
The electrode arm included with the HI-6421/P DO meter can be mounted to either side of the meter, allowing for further flexibility in placement. This electrode stand is designed to securely hold the probe when measuring a sample of salt or freshwater, helping to ensure accuracy in testing.
Repeatable and reliable parameter measurement
The HI-6421/P provides repeatable, accurate and reliable measurements in freshwater and saltwater samples. This advanced benchtop meter and four-ring probe provide precise readings for DO, BOD, SOUR and OUR.
Complete flexibility
The ability to connect and share data via WiFi and ethernet removes the restriction of placement within the laboratory, with the HI-6000 series not requiring direct connection to a PC or printer. The flexible electrode arm can also be mounted to either side of the unit, saving bench space and allowing the HI-6421/P to be placed up against a wall on either side if required.
Intuitive, practical interface
The HI-6421/P features a comprehensive, easy-to-use interface, with access to a wide range of settings and customisations to tailor this advanced DO meter to your requirements. The menu system includes:
- Network
- Connect and Print
- System
- Custom Users
- User Account Management
- Info Screen
- Log Recall
- Log History and Sharing
- Log Detail
- On-Board Help
Choose from five measurement views
Five purpose-built measurement views are available for the HI-6431/P, enabling you to tailor your measurement screen to the most relevant information:
- Basic View: A view featuring basic information about measurement
- Simple GLP View: Displays basic GLP data, including Including latest calibration date and time, Offset value, average slope and electrode condition.
- Full GLP View: A full GLP display featuring the electrode symbol and used buffers tray in addition to the above visuals.
- Graph View: A plotted graph of the current measurement
- Tabulated View: An organised table of data featuring date, time and notes in a list of recent measurements
One million data point storage
The extensive capacity of the HI-6421/P DO meter allows up to one million individual data points to be stored, inclusive of both date and time stamps. This organised information is available for export in .csv format via WiFi, ethernet, direct connection or USB stick, with no specialist software required to access measurements.
Audible and visual alarm system
The HI-6000 series includes customisable visual and audible alarms within the settings menu. These alarms can be fully tailored to individual requirements, allowing users to define a specific range for samples. Measurements outside of this range will trigger the audible and visual alarms automatically.
Remote connectivity with ethernet and WiFi
In-built WiFi and ethernet connectivity allow the HI-6421/P to transfer data without the need to connect directly to a PC. Digital transfer is available via FTP or email, providing flexibility to send measurements to laboratory offices or directly to clients as required, with no additional steps or software to access the results of testing.
USB C and USB A included
A USB A and USB C connection is included with HI-6000 series meters, both for the connection of peripherals such as keyboards and for the transfer of data. Information can be exported via USB stick or the HI-6421/P can be connected to a laptop, PC or printer to export data in a universal .csv alongside remote WiFi and ethernet connection.
Complete tutorial system
The HI-6421/P has an in-built tutorial system, with both text prompts and video tutorials to suit your preferred learning style. These tutorials cover all of the fundamentals of operating HI-6000 series lab meters, making it easy to start measurement with a minimal learning curve.
User customisability
Customise access and permissions directly on the HI-6000 series meters, with the ability to create both standard and administrator users. Administrators have full control via the Account Management Screen, enabling standard users to have specific permissions or to have limited access to certain functionalities.
FAQs
What instruments are in the HI-6000 range?
The HI-6000 range includes:
- HI-6221 pH and ORP meter
- HI-6321 Conductivity meter
- HI-6421 Dissolved Oxygen meter (also available with polarographic probe)
- HI-6000 Modular Multiparameter meter
Is the HI-6421/P DO meter suitable for laboratory usage?
The HI-6000 series, including the HI-6421/P polarographic DO meter, is specifically designed to be functional and practical in a laboratory environment. These exceptionally accurate, laboratory-grade meters are an ideal solution for industrial applications both within businesses and within the laboratories that provide outsourced services for clients within industries.
What are the key features of the HI-6421/P?
Some of the key features of the Hanna HI-6421/P include:
- Measures DO, SOUR, OUR and BOD
- Connect via WiFi and ethernet
- Easy-to-use interface
- Space-saving design
- Exceptional repeatability and accuracy
Can I get training on the HI-6421/P meter?
What industries is the HI-6421/P suitable for?
The HI-6421/P lab meter is a versatile solution for accurately measuring dissolved oxygen in salt and freshwater. This advanced meter for DO is suitable for a range of different niches and applications that require the measurement of natural water, wastewater and other kinds of water.
How do I book a demonstration with Hanna Instruments?
Specifications
| HI-6421 - DO (HI-7641133 Optical probe) | |
|---|---|
| Range | 0.00 to 50.00 mg/L (ppm) concentration; 0.0 to 500.0 % saturation |
| Resolution | 0.01 mg/L (ppm); 0.1 % saturation |
| Accuracy | from 0.00 to 20.00 mg/L (ppm) 1.5 % of reading or ±0.01 mg/L (ppm), whichever is greater from 20.00 to 50.00 mg/L (ppm) ±5 % of reading from 0.0 to 200.0 % saturation ±1.5 % of reading or ±0.1 %, whichever is greater from 200.0 to 500.0 % saturation ±5 % of reading |
| HI-6421P – DO (HI-764833 Polarographic probe) | |
| Range | 0.00 to 90.00 mg/L (ppm) concentration; 0.0 to 600.0 % saturation |
| Resolution | 0.01 mg/L (ppm); 0.1 % saturation |
| Accuracy | ±1.5 % of reading ±1, least significant digit |
| Barometric Pressure | |
| Range | 450 to 850 mmHg; 600 to 1133 mBar; 60 to 133 kPa; 17 to 33 inHg; 8.7 to 16.4 psi; 0.592 to 1.118 atm |
| Resolution | 1 mmHg; 1 mBar; 1 kPa; 1 inHg; 0.1 psi; 0.001 atm |
| Accuracy | ±3 mmHg within ±15 % from the calibration point ±3 mmHg ±1 least significant digit |
| Temperature | |
| Range | −20.0 to 120.0 °C −4.0 to 248.0 °F 253.0 to 393.0 K |
| Resolution | 0.1 °C; 0.1 °F; 0.1 K |
| Accuracy | ±0.2 °C; ±0.4 °F; ±0.2 K |
| DO Calibration | |
| Points | DO optical One or two points automatic calibration at 100% (8.26 mg/L) and 0% (0 mg/L). Single point manual using a value entered by the user in % saturation or mg/L. DO polarographic Automatic-two points / User standard-single point |
| Standards | 0 and 100% saturation |
| Reminder | Disabled Daily: 0 min. to 23 hours and 59 min. Periodic: 1 min. to 500 days, 23 hours and 59 min. |
| Temperature Compensation | Automatic or Manual |
| Salinity Compensation (Optical DO only) | Automatic from 0 to 70 PSU (manually set) 0.0 to 70.0 % / 0.0 to 45.0 g/L / 0.0 to 42.0 psu |
| Reading | |
| Modes | Direct Direct/Autohold |
| Stability criteria | Accurate Medium Fast |
| Isopotential | 7.000 or 4.010 |
| Sampling rate | 1000 ms |
| DO Views | |
| Basic | Measurement (DO, Temperature) Stability status |
| Simple GLP | Basic view information Last calibration date, offset, average slope |
| Full GLP | Simple GLP information and calibration point details |
| Table | Measurements updated every second are displayed in table |
| Graph (Plot) | Measurement versus time graph can be panned or zoomed (pinch-to-zoom technology) |
| Logging | |
| Type | Automatic, Manual, Autohold |
| Number of records | 50 000 maximum per file Stores at least 1 000 000 data points per user |
| Automatic interval | 1, 2, 5, 10, 30 seconds 1, 2, 5, 10, 15, 30, 60, 120, 150, 180 minutes |
| Sample ID | Incremental mode |
| Export option | .csv file format |
| Users | Up to 9 users and the default administrator account |
| Connectivity | |
| USB-A | 2 ports for keyboard input or USB thumb drive |
| USB-C | 1 port for PC connectivity and USB-C type thumb drive |
| Wi-Fi & Ethernet | FTP Web server Log transfer and download Email |
| RS232 | Connecting peripherals |
| Power supply | DC adapter 100-240AC to 24VDC 2.5A |
| Environment | 0 - 50 °C / 32 - 122 °F / 273 - 323 K maximum 95% RH non-condensing |
| Dimensions | 205 x 160 x 77 mm (8.0 x 6.2 x 3.0 “) |
| Weight | Approximately 1.2 kg (26.5 lbs.) |
| Ordering Information | HI-6421 is supplied with HI-7641133 optical dissolved oxygen probe (OPDO®); HI-764060 electrode holder; capillary pipette; 24 VDC power adapter; USB-C to USB-A cable; probe quality certificate; quick reference guide with instrument quality certificate. HI-6421P is supplied with HI-764833 polarographic probe; HI-764060 electrode holder; capillary pipette; 24 VDC power adapter; USB-C to USB-A cable; probe quality certificate; quick reference guide with instrument quality certificate. |
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Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.