The HI9813-51 portable meter features a large LCD that displays either pH, EC, TDS or temperature readings along with tutorial instructions. The pH readings are displayed with a 0.1 resolution and an accuracy of +/-0.1 pH while the EC and TDS readings are displayed with a 0.01 mS/cm and 1 ppm (mg/L) resolution and 2% full-scale accuracy. The EC range of the HI9813-51 is from 0.00 to 4.00 mS/cm and TDS is from 0 to 1999 ppm. The temperature correction coefficient (?) is fixed at 2 %/oC and allows for automatic temperature compensated measurements of EC and TDS. The HI9813-5 is a basic 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 a battery life indicator as well as on-screen tutorial messages. The supplied HI1285-51 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 HI9813-51 is a versatile meter for the agricultural, greenhouse and hydroponic uses.
HI1285-51 polypropylene body amplified pH electrode with built-in EC/TDS and temperature sensors
The HI9813-51 is supplied with a polypropylene body pH/EC/TDS/temperature probe. The pH, EC, TDS, and temperature sensor are housed in a single body that connects to the meter with a DIN connector.
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 number 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 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
Waterproof
Automatic Temperature Compensation
- All readings are compensated for variations in temperature
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
| Specification Name | Detail |
|---|---|
| sku | HI9813-51 |
| pH Range | 0.0 to 14.0 pH |
| pH Resolution | 0.1 pH |
| pH Accuracy (@25°C/77°F) | ±0.1 pH |
| pH Calibration | Manual, 1-point |
| Temperature Range | 0.0 to 70.0°C |
| Temperature Resolution | 0.1°C |
| Temperature Accuracy (@25°C/77°F) | ±0.5°C |
| Temperature Calibration | Automatic from 0 to 70°C with ß=2% / °C |
| EC Range | 0 to 4000 µS/cm |
| EC Resolution | 0.01 mS/cm |
| EC Accuracy (@25°C/77°F) | ±2% F.S. |
| EC Calibration | Manual, 1-point |
| TDS Range | 0 to 1999 ppm (mg/L) |
| TDS Resolution | 1 ppm |
| TDS Accuracy (@25°C/77°F) | ±2% F.S. ppm |
| TDS Conversion Factor | Variable, automatically adjusted from 0.56to 0.78 based on actual EC readings (based on 442 curve for natural water) |
| TDS Calibration | Manual, 1-point |
| Power Supply | 1 x 9V Alkaline / approximately 150 hours of continuous use |
| Environment | 0 to 50°C (32 to 122 °F); 100% RH |
| Dimensions | 145 x 80 x 36 mm (5.7 x 3.1 x 1.4 “) |
| Weight | 230 g (8.1 oz.) |
| Warranty | 2 years |
| Recommended Probe | HI1285-51 combination, amplified pH /EC/TDS/temperature probe with built-in temperature sensor, 8-pin DIN connector and 1 m (3.3’) cable |
