Hach PHC745 User manual

DOC022.53.80435
PHC745
05/2021, Edition 2
User Manual

Table of Contents
Section 1 Product overview................................................................................. 3
Section 2 Specifications........................................................................................ 3
Section 3 Safety information............................................................................... 4
3.1 Intended use ....................................................................................................... 4
3.2 Use of hazard information..................................................................................... 4
3.3 Precautionary labels............................................................................................. 5
3.4 Product hazards.................................................................................................... 5
Section 4 Preparation for use.............................................................................. 5
4.1 Operate the sleeve junction.................................................................................. 7
Section 5 Calibration.............................................................................................. 8
5.1 Calibration notes................................................................................................... 8
5.2 Calibration procedure........................................................................................... 9
Section 6 Sample measurement .................................................................... 10
6.1 Sample requirements.......................................................................................... 10
6.2 Sample measurement notes............................................................................... 10
6.3 Sample measurement procedure....................................................................... 10
Section 7 Verify the calibration........................................................................ 11
7.1 Verification procedure......................................................................................... 11
Section 8 Maintenance......................................................................................... 12
8.1 Clean the probe.................................................................................................. 12
8.1.1 Clean the sleeve junction......................................................................... 13
8.2 Fill the probe....................................................................................................... 14
8.3 Add KCl crystals to the probe............................................................................. 14
8.4 Replace the filling solution.................................................................................. 16
8.5 Soak procedure for dry probes........................................................................... 17
8.6 Storage............................................................................................................... 17
Section 9 Troubleshooting ............................................................................... 18
Section 10 Consumables..................................................................................... 19
10.1 Recommended standards................................................................................. 19
10.2 Accessories...................................................................................................... 20
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Table of Contents
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Section 1 Product overview
The Intellical PHC745 pH probes are digital, combination electrodes that measure the pH of water
samples. The glass sleeve junction keeps the reference junction clean for measurements in
wastewater influent, emulsions and viscous liquids. The probes use the Red Rod technology and a
saturated KCl electrolyte for high performance. The probes are refillable and have a built-in
temperature sensor. A 59-mL bottle of reference electrolyte filling solution (saturated KCl solution) is
supplied with the probe. Refer to Figure 1.
Note: Do not use the probe to measure the pH of organic solvents or very alkaline samples.
Figure 1 Probe overview
1 Probe soaker bottle with storage solution 5 Electrode filling and storage solution
2 Filling-hole plug 6 Glass sleeve junction
3 Protective tape and filling hole 7 Glass bulb and temperature sensor
4 Cable
Section 2 Specifications
Specifications are subject to change without notice.
Specifications Details
Probe type Digital combination glass pH probe with refillable electrolyte and built-
in temperature sensor
pH range 0 to 14 pH
pH accuracy ±0.01 pH
Reference type Red Rod (Ag/AgCl in protective tubes)
Reference junction Glass sleeve
Slope –59 mV/pH (85 to 115% at 25 °C (77 °F) per Nernstian theoretical
value)
Isopotential point 6.00 pH
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Specifications Details
Sodium (alkalinity) error <0.3 pH at pH 13 in 0.1 M NaOH
Temperature accuracy ±0.3 °C (±0.54 °F)
Temperature sensor type 30 kΩ NTC thermistor
Operating temperature –10 to 110 °C (14 to 230 °F)
Storage temperature 5 to 40 °C (41 to 104 °F)
Minimum immersion depth 18 mm (0.71 in.)
Body material Glass
Electrolyte filling solution Saturated KCl
Storage solution Saturated KCl
Cable connection M12 digital output and connector
Dimensions Diameter: 12 mm (0.47 in.)
Length: 200 mm (7.9 in.) total; 103 mm (4.1 in.) below head
Cable length: 1 m (3.3 ft)
Weight (includes cable) ~0.4 kg (0.9 lb)
Warranty 1 year on the probe. This warranty covers manufacturing defects, but
not improper use or wear.
Certifications CE, FCC/ISED
Section 3 Safety information
3.1 Intended use
The Intellical probes are intended for use by individuals who measure water quality parameters in the
laboratory. The Intellical probes do not treat or alter water.
3.2 Use of hazard information
D A N G E R
Indicates a potentially or imminently hazardous situation which, if not avoided, will result in death or
serious injury.
WARNING
Indicates a potentially or imminently hazardous situation which, if not avoided, could result in death
or serious injury.
CAUTION
Indicates a potentially hazardous situation that may result in minor or moderate injury.
N O T I C E
Indicates a situation which, if not avoided, may cause damage to the instrument. Information that
requires special emphasis.
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3.3 Precautionary labels
Read all labels and tags attached to the instrument. Personal injury or damage to the instrument
could occur if not observed. A symbol on the instrument is referenced in the manual with a
precautionary statement.
Electrical equipment marked with this symbol may not be disposed of in European
domestic or public disposal systems. Return old or end-of-life equipment to the
manufacturer for disposal at no charge to the user.
3.4 Product hazards
CAUTION
Chemical exposure hazard. Obey laboratory safety procedures and wear all of the
personal protective equipment appropriate to the chemicals that are handled. Refer to
the current safety data sheets (MSDS/SDS) for safety protocols.
CAUTION
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local,
regional and national regulations.
CAUTION
Personal injury hazard. Glass components can break. Handle with care to prevent cuts.
Section 4 Preparation for use
N O T I C E
Make sure to remove the protective tape from the filling hole of new probes. A probe with a blocked
filling hole will not operate correctly.
New probes are filled with electrolyte filling solution and have a soaker bottle that contains storage
solution to keep the glass bulb and reference junction hydrated. Prepare the probe for calibration and
measurement as follows.
1. Remove the protective tape from the filling hole. Refer to Figure 2.
Note: Put the soaker bottle on the soaker bottle holder when not in use.
2. Rinse the reference junction and glass bulb with deionized water. Blot dry with a lint-free cloth.
3. If the inner filling solution is low, add more filling solution. Refer to Fill the probe on page 14.
4. If the level of KCl crystals in the probe is less than approximately 0.5 cm (0.2 in.), or for
measurements at high temperatures (> 60 °C (140 °F), add more KCl crystals. Refer to Add KCl
crystals to the probe on page 14.
5. Invert the probe to make sure that the KCl crystals move freely through the liquid. If necessary,
shake the probe to loosen the crystals.
6. Move the sleeve junction up and down to make sure that electrolyte flows from the sleeve
junction (refer to Operate the sleeve junction on page 7).
7. Soak the probe in a warm pH 4 buffer solution for approximately 1 hour to condition the probe.
Note: If probe stabilization is slow, soak the probe for 2 hours in a warm pH 4 buffer solution. The soak
procedure helps to dissolve KCl crystals in the reference junction.
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8. Make sure that the meter has the correct date and time settings. The service-life time stamp in
the probe comes from the date and time settings in the meter.
Note: Some meters automatically open the date and time settings when the meter starts for the first time, or
after battery replacement.
9. Connect the probe to the meter.
10. Remove the filling-hole plug before use. Keep the level of the electrolyte filling solution above the
level of the measurement liquid during use. Refer to Figure 3.
Note: For measurements in low ionic strength (LIS) samples, soak the probe for a maximum of 5 minutes in the
sample before use.
Figure 2 Remove the protective tape
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Figure 3 Probe position during use
1 Filling hole 3 Level of calibration solution or sample
2 Level of electrolyte filling solution 4 Sleeve junction
4.1 Operate the sleeve junction
N O T I C E
Close the sleeve junction and fill the electrolyte after each use. The probe can become permanently
damaged if all of the electrolyte drains from the probe.
Loosen the sleeve junction during calibration and measurement to make sure there is a good
electrical connection between the inner electrolyte and the standard or sample. Lightly move the
sleeve junction up or down a small distance to change the flow rate of the electrolyte. A high
electrolyte flow rate gives a fast response in different sample types but uses a high volume of
electrolyte. Make sure that the electrolyte does not fully drain from the probe.
1. Hold the probe over a beaker or container.
2. Lift the sleeve junction until drops of electrolyte flow out.
3. Lightly push the sleeve junction down to the initial position. Refer to Figure 4.
Note: Do not loosen the sleeve junction too much. If the electrolyte flow is too high, the electrolyte will drain
quickly and the probe must be filled frequently. Do not tighten the sleeve junction too much. If the electrolyte
flow is too low, the electrolyte will not flow and the electrical connection will not be sufficient.
4. To close the reference junction, slowly move the sleeve junction down until the electrolyte flow
stops.
Note: Always close the sleeve junction when the probe is not in use.
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Figure 4 Sleeve junction operation
Section 5 Calibration
The procedure that follows is applicable to meters that can connect to Intellical pH probes. Refer to
the applicable meter documentation for meter operation and probe-specific settings.
5.1 Calibration notes
Read the notes that follow before calibration:
• Use prepared pH buffer solutions or mix pH buffer powder pillows with deionized water for
calibration. Discard the prepared buffer solutions after each calibration.
• Use two or three buffer solutions for best results. Two buffer solutions are sufficient if the expected
sample pH is between the pH of the two buffer solutions. The sequence in which the pH buffer
solutions are used is not important. Use buffer solutions that are 2 or more pH units apart.
• For a one-point calibration, use a pH buffer near the expected sample pH.
• Use the default calibration options or change the options in the probe settings menu.
• Use the single display mode for calibration when more than one probe is connected to the meter (if
applicable).
• Calibrate the probes and verify the calibration regularly for best results. Use the meter to set
calibration reminders.
• The calibration data is stored in the probe. When a calibrated probe is connected to a different
meter with the same calibration options, a new calibration is not necessary.
• Air bubbles below the sensor when in solution can cause a slow response or error in the
calibration. Make sure to remove air bubbles during calibration.
• The pH buffer solutions have known pH values at different temperatures. The meter uses the mV
and temperature readings of the probe in the pH buffer solutions to calculate a calibration slope.
During measurements, the meter adjusts the slope for the sample temperature to determine the
pH value of the sample.
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