The HI12302 HALO is a revolutionary pH electrode that incorporates Bluetooth Smart (Bluetooth 4.0) wireless technology with an application-specific design. This electrode has many features that makes it ideal for use in the field or on the production floor. These features include general purpose (GP) glass, spheric bulb, integrated temperature sensor, PEI body, and double reference junction with silver-free gel electrolyte.
General Purpose Glass Formulation
General Purpose (GP) glass, as the name implies, is a standard glass formulation that is used for general use. A pH electrode with GP glass will have a resistance of 100 megaohms at 25°C and is suited for measuring pH of samples that are at ambient temperatures. The HI12302 is suitable to use with samples that measure from -5 to 70°C (23 to 158°F).
Spheric Glass Tip
The spheric bulb is for general purpose use within laboratory environments and applications that measure aqueous solutions due to its large surface area. Other tip shapes include conic for penetration and flat tip for surface measurements.
Built-In Temperature Sensor
HI12302 features a built-in thermistor temperature sensor that is in the tip of the indicating pH electrode. A thermistor temperature sensor provides for a high accuracy temperature reading and should be as close as possible to the indicating pH electrode in order to compensate for the effect that temperature has on the membrane potential as predicted by the Nernst equation. By having an accurate reading it is possible to provide a temperature compensated reading.
The body of the HI12302 is composed of polyetherimide (PEI) resin. PEI is suitable for a wide range of applications and excels in field measurements due to its durability. The shielding around the spherical glass tip minimizes breakage due to accidental bumping or dropping of the electrode. PEI is a high quality plastic that is chemically resistant to many aggressive chemicals.
Single Ceramic Double Junction Reference
The HI12302 is a double junction design. pH electrodes are available as single junction or double junction. See below for a complete description of the differences. The junction also known as a salt bridge is necessary component of the electrical circuit. The movement of ions must flow through the junction for a steady reading. The outer portion of the reference cell has a single ceramic frit. A single ceramic junction allows the gel electrolyte to flow at a rate of 15 to 20 μL/hour.
Conventional electrodes are normally single junction. As depicted by the figure above, these electrodes have only a single junction between the internal reference wire and the external solution. Under adverse conditions, such as high pressure, high temperature, highly acidic or alkaline solutions, the positive flow of the electrolyte through the junction is often reversed resulting in the ingress of sample solution into the reference compartment. If this is left unchecked, the reference electrode can become contaminated, leading to complete electrode failure. Another potential problem with single junction electrodes is the clogging of the junction due to silver chloride (AgCl) precipitation. Silver can be easily precipitate in samples that contain Tris buffer or heavy metals. When the electrolyte solution makes contact with the sample, some AgCl will precipitate on the external face of the junction. The result is drifty readings obtained from the sensor.
Hanna’s double junction system, as the name implies, has two junctions, only one of which is in contact with the sample as shown in the figure. Under adverse conditions, the same tendency of sample ingress is evident. However, as the reference electrode system is separated physically from the intermediate electrolyte area, the contamination of the electrode is minimized. The likelihood of clogging of the junction is also reduced with a double junction electrode since the outer reference cell uses a fill solution that is “silver-free.” Since there is no silver present, there is no precipitate that can form to clog the junction.
Hanna Lab App
HALO pH electrodes can connect with HI2202 edgeblu meter or a compatible Apple or Android device running the Hanna Lab App.
The Hanna Lab App turns a compatible Apple or Android device into a full-featured pH meter when used with the Hanna HALO pH probe with Bluetooth Smart technology. Functions include calibration, measurement, data logging, graphing and data sharing. Measurement and logging of pH and temperature at one second intervals start as soon as the probe is connected. Measurements can be displayed alone on the display, with tabulated data, or as a graph. The graph can be panned and zoomed with pinch-to-zoom technology for enhanced viewing.
The Hanna Lab App incorporates a probe calibration using up to five pH buffers that are automatically recognized and temperature corrected to 25.0ºC during calibration.
Display of pH and temperature updated every second. Readings are automatically saved to a history file every hour, limited only by the available memory on the device.
Fluid, Dynamic Graphing
Measurement can be displayed with tabulated data or a graph on the display. The graph axes may be expanded using pinch-to-zoom technology for enhanced viewing.
Connecting the HALO probe to the Hanna Lab App is simple. Tap the Bluetooth icon in the top-right corner to view all available HALO probes then press the button on your HALO probe. Select the newly discovered HALO probe from the list of available probes. If a previously associated probe is in discovery mode when the app is opened it will connect to that probe automatically.
GLP (Good Laboratory Practice)
Displays date and time of current calibration, probe offset, and average slope, along with calibrated buffers, mV values, temperature and slopes between each buffer.
Calibration Reminder & Measurement Alarms
The Hanna Lab App alerts you when HALO needs calibration or if a measurement threshold is exceeded.
Log & Share Data
Saved log files may be annotated with measurement specific information. Data is easily shared via email in CSV format.
Help & Tutorials
Demo probe mode helps you explore features of the Hanna Lab App. General app information, General HALO information, pH tutorial, maintenance tutorial, and contact information are available in help.
Hanna Lab App Features/Benefits:
Connects to HALO electrodes via Bluetooth Smart Technology (Bluetooth 4.0)
Up to five-point pH calibration with seven standard pH buffers available
- Alerts you when HALO needs calibration
- Displays pH and temperature updated every second
- Displays date and time of current calibration along with probe offset and average slope
- Displays date and time of current calibration, probe offset and average slope along with calibrated buffers, mV values, temperature and slopes between each buffer
- Measurement can be displayed with tabulated data or as a graph. The graph axes may be expanded using pinch-to-zoom technology for enhanced viewing
One button sample tagging
- Alerts you if the measurement threshold is exceeded
- Pressing either the probe icon in the Hanna Lab App or button on the HALO pH probe will tag sample data for easy reference
- Saved log files may be annotated with measurement specific information
- Data is autosaved every hour
- All data since last autosave
- Annotations only
- All data within a timed interval
- Annotations only within a timed interval
Help and tutorials:
- Demo probe mode to help explore features of the Hanna Lab App
- General app information
- General HALO information
- pH tutorial
- Maintenance tutorial
- Contact information
Measurement Range pH: 0 to 12 Reference Cell Type double, Ag/AgCl Junction Type/Flow Rate ceramic, single Type of Electrolyte gel Body Material PEI Tip / Shape spheric Matching Pin no Max. Pressure 2 bar Temperature Operating Range -5 to 70°C (23 to 158°F) Body Length/Overall Length 100 mm / 165 mm Temperature Sensor yes Outer Diameter 12 mm Connector Type Bluetooth Smart (Bluetooth 4.0), 10 m (33') range Battery Type/Life CR2032 3V lithium ion / approximately 500 hours Amplifier yes Recommended Use field applications Notes Environment: 0.0 to 50.0°C (32.0 to 122.0°F), electronic module is not waterproof
HannaLab App Measurement
Range -2.000 to 16.000 pH / ±800 mV / -20.0 to 120.0 ºC *(will be reduced to actual probe/sensor limits) Resolution 0.1, 0.01, 0.001 pH / 1, 0.1 mV Accuracy (@25ºC/77ºF) ±0.005 pH / ±0.3 mV Calibration Points Up to five points with seven standard buffers Calibration Buffers 1.68, 4.01, 6.86, 7.01, 9.18, 10.01, 12.45 pH Temperature Compensation Automatic from -5.0 to 100.0 ºC / 23.0 to 212.0 ºF *(will be reduced to actual probe/sensor limits) Compatibility/System Requirements Android: Compatible with most devices equipped with Bluetooth Smart Technology (Bluetooth 4.0) and running Android 4.3 or later.
iOS: Compatible with iPad (3rd generation or newer), iPhone (4S or newer), iPod Touch (5th generation or newer)
Download Information Hanna Lab App is available free from the Play Store or App Store
Ordering Information HI12302 (HALO) is supplied with storage solution, cleaning solution, pH 7.01 buffer solution, pH 4.01 buffer solution, battery, quality certificate and instruction sheet.
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