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MX2501 pH and Temperature data logger designed for long-term monitoring in both fresh water and saltwater environments

Data Logger designed for long-term monitoring of pH and temperature in estuaries, lakes, streams, rivers, and oceans. Affordable and compact logger to collect higher resolution field data leveraging BLE technology.

MX2501 pH and Temperature data logger

The HOBO MX2501 pH and Temperature data logger is an affordable and compact logger for long-term monitoring of pH in estuaries, lakes, streams, rivers, and oceans. Using Bluetooth Low Energy® (BLE) technology, the MX2501 pH Logger communicates wirelessly with the free HOBOconnect app. Logger setup, calibration, and data offload can be done quickly and easily using your mobile phone and Windows computer. A guided pH calibration process on the HOBOconnect app makes an otherwise complicated process easier to follow. This affordable and compact logger dramatically cuts the time and effort needed to collect field data, while also offering higher resolution data. (NOTE: pH electrodes should always be stored in storage solution when not deployed.)

 

Highlighted Features

• Guided pH calibration following on-screen prompts in HOBOconnect app
• Rugged PVC housing for deployment in both freshwater and saltwater environments
• Quick and easy data offload via Bluetooth Low Energy (BLE) to mobile devices or Windows computers
• Water detection system for longer battery life and less maintenance
• Potentiometric pH electrode with plastic body, gel electrolyte, and double cloth junction
• User-replaceable battery, pH electrode, and anti-biofouling copper guard
• Accuracy of ±0.10 pH units within ±10°C of temperature at calibration

 
 Specifications
pH Sensor

 

Range

Accuracy

Resolution

Response Time

Sample Ionic Strength

      pH                                                                                                    mV

2.00 to 12.00 pH                                                                              -512 to 512 mV

±0.10 pH units within ±10°C of temperature at calibration            ±0.20 mV

0.01 pH                                                                                             0.02 mV

1 minute typical to 90% at constant temperature in stirred water

≥ 100 µS/cm

Temperature Sensor
Range -2° to 50°C (28.4° to 122°F)
Accuracy ±0.2°C (±0.36°F)
Resolution 0.024°C at 25°C (0.04°F at 77°F)
Response Time 7 minutes typical to 90% in stirred water
Logger

Operating Range

-2° to 50°C (28.4° to 122°F) — non-freezing

Buoyancy Fresh water: 13.6 g (0.48 oz) negative
Salt water: 19.6 g (0.69 oz) negative

Waterproof

Water Detection

To 40 m (131.2 ft)

Water conductivity level of 100 µS/cm or greater necessary for reliable detection of water. Deionized water or water below 100 µS/cm may not be detected

Radio Power

Transmission Range

Wireless Data Standard

1 mW (0 dBm)

Approximately 30.5 m (100 ft) line-of-sight in air

Bluetooth Low Energy (Bluetooth Smart)

Logging Rate

Logging Modes

Memory Modes

Start Modes

Stop Modes

Time Accuracy

Battery Type

1 second to 18 hours

Fixed interval (normal, statistics) or burst

Wrap when full or stop when full

Immediate, push button, date & time, or next interval

When memory is full, push button, date & time, or after a set logging period

±1 minute per month 0° to 50°C (32° to 122°F)

One AA 1.5 Volt, user-replaceable

pH Electrode Typical Minimum Life 6 months in sample with ionic strength ≥ 100 µS/cm

Memory

Full Memory Download Time

152 KB (43,300 measurements, maximum)

Approximately 60 seconds; may take longer the farther the mobile device is from the logger

Dimensions 22.86 x 4.27 cm (9.0 x 1.68 inches); mounting hole 0.64 cm (0.25 inches)
Weight 268.2 g (9.46 oz)
Wetted Materials Logger: PVC housing and sensor end cap, polycarbonate closure caps and mounting end cap with a TPE switch
pH electrode: plastic-bodied with Pellon® junctions and gel electrolyte, glass pH sensor bulb
Environmental Rating IP68