Portable Waterproof pH/EC/TDS Meter (High Range) - HI991301

In stock
The HI991301 is a light weight, portable pH, conductivity (or total dissolved solids) and temperature meters for portable applications requiring both a pH and conductivity (or TDS) measurement. Applications include measurements for greenhouses irrigation, hydroponics and groundwater monitoring from agriculture nutrient pollution. The HI991301 meters feature 2 button operation and are simple to use. All operations and settings, including calibration buffers and temperature scale selections, are made through these 2 buttons. They have a waterproof and compact casing rated for IP67 conditions and a large Tri-line display. The meters have automatic pH calibration at one or two points and a single conductivity calibration. Other user selectable features include different TDS factors from 0.45 to 1.00, and a range of temperature coefficients (β) from 0.0 to 2.4% for better conductivity or TDS solution temperature compensation. These meters are supplied with a multi-parameter probe specifically designed for these meters. To increase conductivity accuracy, two meter models are available, with different conductivity ranges, for applications from purified to brackish waters.

pH Meters and  EC/TDS Meters

• Simultaneous, pH, EC/TDS and temperature measurements on a large three-line LCD display;

• User-friendly Design With only two buttons, meter operation could not be simpler. Two buttons allow you to quickly adjust settings, select the measurement range, and choose calibration buffer sets

• Watertight Connection A Quick Connect DIN connector makes attaching and  removing the probe simple and easy. The rubber coating protects the cable and creates a sealed connection for added reliability.

• Probe Condition An on-screen indicator provides visual confirmation that your probe is working at its best.

• Large LCD A multilevel display provides ata-glance readings of your most important numbers from any angle

• Durable IP67 waterproofcCasing Designed to withstand the knocks, drops, and spills of real life, the new IP67 body ensures top performance in any environment. These meters are totally protected against dust and water intrusion from any direction. • On-screen calibration tags

• mV of pH measurement for electrode check

• Selectable temperature unit (°C or °F)

• Battery life indication and low battery detection



The HI12883 multi-parameter probe, incorporates a domed shaped pH bulb rated from 0-13 pH, a single junction Ag/AgCl reference electrode with gelled electrolyte and a retractable cloth wick junction, a graphite EC/TDS cell, and a temperature sensor in one convenient, rugged polypropylene body. In addition, to ensure against interference from transient electrical noise to pH, a solidstate preamplifier is integrated into the probe. The probe is rated from 0 to 50°C.

HI1288 amplified pH electrode

• 3 sensors in a single probe

• Pre-amplified pH electrode for resistance to electrical noise

• Extractable cloth junction to clear any clogging

• Graphite EC/TDS sensor The HI991301 and HI991300 are supplied with an amplified polypropylene body pH/EC/TDS/temperature probe. The built in amplifier will reduce the effects of electrical noise on the high impedance pH measurement. Examples of sources of electrical noise include rectifiers, motors and ballasts. The HI1288 pH electrode also features an extractable cloth junction. Every pH electrode has a junction. Many use a single ceramic frit which acts as a barrier between the inside reference cell to the outside sample. This barrier allows for a diffusion electrolyte that is necessary for the pH measurement. Any clogging of the junction will result in a reduced diffusion and as a result the readings will become erratic. Most probes will have to have this junction cleaned and if not possible then the probe has to be replaced. The extractable cloth junction of the HI1288 allows for the renewing of the junction. Simply extract ⅛” of the junction by pulling on the junction will expose a new portion. Any clogging that was present will be cleared and the response time will be back to normal extending the life of the pH electrode. The EC/TDS sensor is made of graphite. A common problem with amperometric sensors is a polarization effect. With amperometric sensors there are two poles in which a voltage is alternated. The positive and negative ions in the solution migrate to one of the negative or positive poles. When the charges build up on one of these poles a polarization effect occurs. Having a conductivity sensor made of graphite reduces the polarization effect.






pH Range 

-2.00 to 16.00 pH / -2.0 to 16.0 

pH Resolution 

0.01 pH / 0.1 

pH Accuracy 

±0.02 pH / ±0.1 

pH Calibration 


automatic, 1 or 2 points choose between 2 sets of buffers (standard: 4.01; 7.01; 10.01 or NIST: 4.01; 6.86; 9.18) 

pH/mV Range 


MV Resolution 


mV Accuracy 


mV EC Range 

0.00 to 20.00 mS/cm 


0.01 mS/cm 


±2% F.S 




0.00 to 10.00 ppt (g/L) 


0.01 ppt (g/L) 


±2% F.S. 

Temperature Range 

-5.0 to 105.0°C / 23.0 to 221.0°F 




±0.5°C / ±1.0°F 



EC/TDS automatic, one point at: 1413 µS/cm or 1382 ppm (CONV=0.5) or 1500 ppm(CONV=0.7) 

Temperature Compensation 


pH automatic EC/TDS automatic with β selectable from 0.0-2.4%/°C with 0.1 increments 

General Meter 


TDS Conversion Factor automatic with β selectable from 0.0-2.4%/°C with 0.1 increments 



HI12883 pH/EC/TDS/temperature sensor, DIN connector and 1 m (3.3’) cable 


1.5V AAA (3) /approx. 600 hours of continuous use 


user selectable: after 8 min, 60 min or disabled 


0 to 50°C (32 to 122°F); RH max. 100% 


154 x 63 x 30 mm (6.1 x 2.5 x 1.2”) 


196 g (6.91 oz.) 



Protection Rating 


Ordering information 


HI991301 is supplied with HI12883 pH/EC/TDS probe with built-in temperature sensor, DIN connector and 1m (3.3’) cable, pH 4.01 and 7.01 buffer sachets, HI70030 12880 μS/cm and HI70038 6.44 ppt calibration solution sachets, HI700601 electrode cleaning solution sachets (2), 100 mL beaker, 1.5V AAA batteries (3), calibration certificate of meter, calibration certificate of probe, instruction manual and HI710142 rugged carrying case.