Hanna Instruments HI9812-51 User manual

INSTRUCTION MANUAL
HI9812-51
Portable
pH / EC / TDS / Temperature
Meter

All rights are reserved.
Reproduction in whole or in part is prohibited without the written
consent of the copyright owner, Hanna Instruments Inc., Woonsocket,
Rhode Island, 02895, USA.
Thank you for choosing a Hanna Instruments®product.
Please read this instruction manual carefully before using
this instrument. This manual will provide you with the
necessary information for correct use of this instrument, as
well as a precise idea of its versatility.
If you need additional technical information, do not
hesitate to e‑mail us at [email protected] or view
our contact list at www.hannainst.com.
Dear
Customer,

3
TABLE OF CONTENTS
TABLE OF CONTENTS
1. Preliminary Examination ......................................................... 4
2. General Description ................................................................. 4
3. Functional Description & LCD Display ....................................... 5
4. Specifications ......................................................................... 6
5. General Operations ................................................................. 8
5.1. Battery Replacement .................................................... 8
5.2. Connecting the Electrode ............................................... 9
5.3. Turning the Meter On .................................................... 9
5.4. Sensor Preparation & Conditioning ................................ 9
6. Calibration ........................................................................... 10
6.1. pH ............................................................................ 10
6.2. EC / TDS .................................................................... 11
7. Measurement ....................................................................... 12
7.1. pH ............................................................................ 12
7.2. EC / TDS .................................................................... 12
7.3. Temperature .............................................................. 13
7.4. Warnings .................................................................. 13
8. pH Values at Various Temperatures ........................................ 14
9. Probe Maintenance ............................................................... 15
10. Accessories ........................................................................ 16
Certification .............................................................................. 17
Recommendations for Users ....................................................... 17
Warranty .................................................................................. 18

4
PrELimiNAry ExAmiNATiON
1. PRELIMINARY EXAMINATION
Remove the instrument and accessories from the packaging and examine
it carefully. For further assistance, please contact your local Hanna
Instruments®office or email us at [email protected].
Each model is delivered in a carrying case and supplied with:
• HI1285-51 pH / EC / TDS / Temperature combination probe and
DIN connector with 1 m (3.3’) cable
• pH 7.01 buffer solution (1 sachet)
• 1413 μS/cm conductivity solution (1 sachet)
• 1382 ppm (mg/L) TDS calibration solution (1 sachet)
• General purpose cleaning solution for Agriculture (2 sachets)
• 100 mL plastic beaker (1 pc.)
• 9V Alkaline battery (1 pc.)
• Instrument quality certificate
• Instruction manual
Note: Save all packing material until you are sure that the instrument
works correctly. Any damaged or defective item must be returned in its
original packing material with the supplied accessories.
2. GENERAL DESCRIPTION
The HI9812-51 is a portable, water resistant meter designed to be paired
with HI1285-51 pH / EC / TDS /Temperature multiparameter probe.
The meter is easy to use, with dedicated keys for measurement modes
that are clearly displayed on the LCD, and knobs for 1-point calibration
of pH and EC. On-screen tutorial messages guide the user through
calibration and measurement.
Main Features
• 3-in-1 combination probe with pH, EC / T DS, and temperature sensors
• Best for hydroponics, greenhouses, farming, and ground water
applications
Probe Features
Polypropylene (PP) body houses three sensors:
pre-amplified pH electrode
• Cloth junction
• Polymer-gel electrolyte
• Low temperature (LT) glass-sensing bulb
amperometric EC/TDS sensor
• Two stainless-steel prongs for determination of conductivity and total
dissolved solids
NTC Thermistor (built-in)
• Ensures that readings are compensated for temperature variations

5
FuNCTiONAL DESCriPTiON & LCD DiSPLAy
3. FUNCTIONAL DESCRIPTION & LCD DISPLAY
pH On/Off
ppm °C
CAL
pH
HI9812-51
EC
TDS
µS/cm
pH
solution and turn the knob
Dip probe in calibration
for current temperature
to match the solution value
1
3
2
5
6
7
89
10
11
4
12
1. 8-pin DIN connector socket
2. Battery-level indicator
3. LCD display
4. On-screen calibration knob indicator
5. pH key – pH range selection
6. µS/cm key – EC range selection
7. ppm (mg/L) key – TDS selection
8. pH calibration knob
9. EC /TDS calibration knob
10. Temperature (°C) selection key
11. On/Off key
12. On-screen tutorial messages

6
SPECiFiCATiONS
4. SPECIFICATIONS
Meter
pH
Range* 0.0 to 14.0 pH
Resolution 0.1 pH
Accuracy ±0.1 pH (@ 25 °C / 77 °F)
Calibration Manual, 1 point
EC
Range* 0 to 1990 μS/cm
Resolution 10 μS/cm
Accuracy ±2% f.s. μS/cm (@ 25 °C / 77 °F)
Calibration Manual, 1 point
Temp. compensation Automatic, from 0 to 70 °C with ß=2% / °C
TDS
Range* 0 to 1990 ppm (mg/L)
Resolution 10 ppm (mg/L)
Accuracy ±2% f.s. ppm (mg/L) (@ 25 °C / 77 °F)
Calibration Manual, 1 point
Temp. compensation Automatic, from 0 to 70 °C with ß=2% / °C
Conversion factor 0.5
Temperature
Range* 0.0 to 70.0 °C
Resolution 0.1 °C
Accuracy ± 0.5 °C
Probe (included) HI1285-51
Battery life Approximately 150 hours of continuous use
Auto shut-off After 8 minutes of non-use
Battery type 1 x 9V Alkaline
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.)
* The range may be limited by the probe’s limits.

7
SPECiFiCATiONS
Probe
Reference Single, Ag/AgCl
Junction Cloth
Electrolyte Gel
Max. pressure 0.1 bar
Range
pH: 0 to 13
EC: 0 to 6 mS/cm
Temperature: 0 to 50°C (32 to 122°F)
Tip shape Spheric, Ø 8.0 mm (0.31”)
Glass type Low Temperature (LT)
Temperature sensor Yes
Amplifier Yes
Body material Polypropylene
Dimensions
Length: 186 mm (7.32”)
Shaft length: 95 mm (3.74”)
Shaft diameter: 16 mm (0.62”)
Cable 1 m (3.3’) with 8-pin DIN connector
Plug DIN
SN: XXXXXXXX
0 to 13 pH / 0 to 50 °C 0 to 6 mS/cm
HI1285-51

8
GENErAL OPErATiONS
5. GENERAL OPERATIONS
5.1. BATTERY REPLACEMENT
To replace the batteries, follow the next steps:
• Turn OFF the instrument.
• Remove the three screws on the back of the instrument to open the
battery compartment.
• Remove the old battery.
• Insert one new 9 V Alkaline battery in the battery compartment while
paying attention to the correct polarity.
• Close the battery compartment using the three screws.
Note: If the battery percentage indicator is empty, the battery level is
too low and the battery needs to be replaced.

9
GENErAL OPErATiONS
5.2. CONNECTING THE ELECTRODE
Align the DIN connector’s 8 pins with the socket and push in the plug.
5.3. TURNING THE METER ON
Turn the instrument on by pressing the On/Off key.
5.4. SENSOR PREPARATION & CONDITIONING
1. Remove the protective cap
2. If the protective cap does not contain any liquid, pour HI70300
Storage solution into the cap.
3. Place it back on the sensor and soak for at least 30 minutes
before use.
4. Rinse with tap water prior to Calibration or Measurement.

10
CALiBrATiON
6. CALIBRATION
6.1. pH
For high accuracy, frequent calibrations are recommended.
Additionally, the pH range should be recalibrated:
• Whenever the electrode is replaced.
• At least once a month.
• After testing aggressive chemicals.
Preparation
Recommended pH calibration standard buffers: pH 4.01, pH 6.86 (NIST),
pH 7.01, pH 9.18 (NIST), pH 10.01.
Use pH 7.01 (HI7007) for neutral samples, pH 4.01(HI7004) for acidic
samples, pH 10.01 (HI7010) for alkaline samples.
Procedure
1. Connect the probe and turn the meter on.
2. Press the pH key to select pH measurement mode.
3. Remove the protective cap and rinse the probe.
4. Pour buffer solution into a clean beaker.
5. Immerse the tip of the probe 4 cm (1 1/2”) in selected buffer and
wait a few minutes for the measurement to stabilize.
6. Press the temperature key (°C) to measure buffer solution
temperature. Take a note of the displayed value.
7. Rotate the calibration knob to adjust the pH value to match written
buffer solution temperature. The pH calibration is now complete.
(see pH VALUES AT VARIOUS TEMPERATURES section).
Note: If, when rotating the knob, required value cannot be reached,
the probe requires cleaning (see the PROBE MAINTENANCE section).
If the issue still persists, the probe requires replacement.