The HI9811-5 is an economical, wateproof, portable meter that measures pH, conductivity (EC), total dissolved solids (TDS) and temperature (°C) with a single probe. The meter operation is simplified with dedicated buttons for measurement modes to be be displayed on the LCD and knobs for single point calibration of pH and EC/TDS. The HI9811-5 is most suitable for agricultural, greenhouse and hydroponic applications.

The HI9811-5 portable meter features a large LCD which displays either pH, EC, TDS or temperature readings along with tutorial instructions. The HI9811-5 is a simplistic pH/EC/TDS meter that is calibrated manually to a single point with the use of two trimmers. pH is calibrated to pH 7.01 while EC/TDS is calibrated to either 1.41 mS/cm (1413 µS/cm) or 1500 ppm. The LCD screen has battery life indicator as well as on-screen tutorial messages.

The supplied HI1285-5 probe is a polypropylene body, amplified pH electrode with a built-in EC/TDS and temperature sensors. The amplifier for the pH electrode prevents interference from humidity and electrical noise from common sources including from motors, ballasts or pumps. The HI9811-5 is a versatile meter best suited for agricultural, greenhouse and hydroponic applications.

HI1285-5 polypropylene body amplified pH electrode with built in EC/TDS and temperature sensors

The HI9811-5 is supplied with a polypropylene body pH/EC/TDS/temperature probe. The pH, EC, TDS, and temperature sensors are housed in a single body that connects to the meter with a DIN connector. This probe is specially engineered with a fiber junction and gel electrolyte to produce a fast response with reduced contamination.

Amplified pH electrode
The pH electrode circuit has a built in amplifier that will reduce the effects of electrical noise on the high impedance pH measurement. Examples of sources of electrical noise include motors, ballasts, and pumps which are common in greenhouses.

Amperometric EC/TDS sensor
The EC/TDS readings are performed by an amperometric sensor. An alternating voltage is applied to the sensor and the amount of current that passes between the two stainless steel pins is dependent upon the amount of salts (fertilizer) present. A greater amount of salt present results in an increase in conductance.

Polypropylene body
The polypropylene body houses all the sensors in a single body design and is durable. The probe is gel filled for maintenance free operation. It does not have to be refilled periodically.

3 sensors in a single probe
Pre-amplified pH electrode for resistance to electrical noise
Gel filled maintenance free pH electrode
Features at-a-glance
Water Resistant
Automatic Temperature Compensation
All readings are compensated for variations in temperature
Variable EC to TDS conversion factor
Factor automatically adjusts from 0.56 to 0.78 based on actual EC readings
Factor based on 442 curve for natural water
Low Battery Indicator
Specifications
pH Range: 0 to 14 pH
pH Resolution: 0.1 pH
pH Accuracy (@25°C/77°F): ±0.1 pH
pH Calibration: manual, one-point through offset trimmer
Temperature Range: 0.0 to 70.0°C
Temperature Resolution: 0.1°C
Temperature Accuracy (@25°C/77°F): ±0.5°C
EC Range: 0.00 to 6000 µS/cm
EC Resolution: 10 µS/cm
EC Accuracy (@25°C/77°F): ±2% F.S.
EC Calibration: manual, one-point through slope trimmer
TDS Range: 0 to 3000 ppm (mg/L)
TDS Resolution: 10 ppm (mg/L)
TDS Accuracy (@25°C/77°F): ±2% F.S.
TDS Conversion Factor: 0.5 ppm (mg/L) = 1 µS/cm
Temperature Compensation: automatic, 0 to 50°C
Temperature Coefficient: β = 2% /°C
Power Supply: 1 x 9V alkaline batteries
Power Consumption: approx. 150 hours of continuous use
Environment: 0 to 50°C (32 to 122°F); 100% RH
Warranty: 2 years
Recommended Probe: HI1285-5 polypropylene body, pre-amplified multiparameter probe with internal temperature sensor, 8-pin DIN connector and 1m cable