pH Checker
Digital pH meter with automatic calibration providing ±0.01 pH accuracy across 0.00-14.00 pH range, featuring replaceable electrodes and automatic temperature compensation.
Louise Corscadden, PhD
Neuroscience · ConductScience
Ask Louise about pH Checker fit, setup, configuration, or quote prep.
Already working with us? Sign in to connect this with My Scientist.
The pH Checker PHB-4 is a digital potentiometric pH meter designed for laboratory determination of pH values and electrochemical potential (mV) in aqueous solutions. The instrument employs standard glass electrode technology with automatic calibration capabilities, providing measurements across the full pH range of 0.00-14.00 with ±0.01 pH accuracy. The meter features automatic temperature compensation from 0-60°C and operates with replaceable pH electrodes for extended service life.
This laboratory instrument supports both single-point and three-point calibration protocols, enabling precise measurements for various analytical applications. The unit displays pH values with 0.01 pH resolution and millivolt readings with 1 mV resolution, accommodating both routine monitoring and precise analytical determinations. The portable design operates on standard AAA batteries while maintaining laboratory-grade measurement performance.
How It Works
The pH Checker PHB-4 operates on potentiometric measurement principles, where pH is determined by measuring the electrical potential developed across a pH-sensitive glass membrane electrode. The glass electrode contains a special pH-sensitive glass membrane that develops a potential proportional to the hydrogen ion activity in the test solution, following the Nernst equation relationship of approximately 59.2 mV per pH unit at 25°C.
The instrument measures the potential difference between the glass indicating electrode and a stable reference electrode, typically integrated into a combination electrode design. The meter's automatic calibration function adjusts for electrode characteristics and drift by measuring the electrode response in standard buffer solutions. Temperature compensation is automatically applied using the built-in ATC function, which corrects for the temperature dependence of the Nernst response and buffer solution pH values.
The digital display presents pH readings to 0.01 pH resolution, while the millivolt function allows direct measurement of electrode potentials for redox measurements or electrode diagnostics. The replaceable electrode design enables users to maintain measurement accuracy by replacing aged or damaged electrodes as needed.
Features & Benefits
Product name
- Ph checker PHB-4
Measuring range
- pH: 0.00~14.00mV: -1999~1999mV°C: 0~60°C
ATC
- 0-60 °C
Calibration point
- 1 or 3 point
Working temperature
- 0~40°C, RHâ¤85%(Without magnetic interference around the meter)
pH electrode
- replaceabl
Calibration
- automatical
Automation Level
- semi-automated
Brand
- ConductScience
Accuracy
- pH: ±0.01pHmV: ±1mV°C: ±1°C
Power/Voltage
- 4X1.5V AAA battery
Research Domain
- Analytical Chemistry
- Environmental Monitoring
- Food Science
- Pharmaceutical QC
Weight
- 0.26 kg
Dimensions
- L: 20.0 mm
- W: 10.0 mm
- H: 5.0 mm
| Feature | This Product | Typical Alternative | Advantage |
|---|---|---|---|
| pH Measurement Accuracy | ±0.01 pH accuracy across 0.00-14.00 range | Entry-level meters often provide ±0.02 pH or lower accuracy | Higher accuracy enables more precise pH control for critical analytical applications and buffer preparation. |
| Calibration Method | Automatic calibration with 1 or 3 point options | Manual calibration requiring operator adjustment of readings | Automatic calibration reduces operator error and ensures consistent standardization across different users. |
| Temperature Compensation Range | Automatic temperature compensation 0-60°C | Limited ATC range or manual temperature adjustment | Wide ATC range accommodates varying laboratory conditions and heated sample measurements. |
| Electrode Serviceability | Replaceable pH electrode design | Fixed electrode requiring complete instrument replacement | Replaceable electrode reduces long-term costs and maintains measurement performance through electrode lifecycle management. |
| Display Resolution | 0.01 pH resolution | 0.1 pH resolution on basic models | Higher resolution enables detection of small pH changes important for quality control and analytical method development. |
| Dual Measurement Mode | pH and millivolt measurement capability | pH-only measurement on basic meters | Millivolt function supports electrode diagnostics and redox potential measurements for expanded analytical capability. |
The pH Checker PHB-4 offers laboratory-grade accuracy with automatic calibration and wide-range temperature compensation. The replaceable electrode design and dual pH/mV measurement capability provide operational flexibility and long-term cost effectiveness for analytical applications.
Practical Tips
Calibrate with fresh buffer solutions at least weekly for critical measurements, and verify calibration with a third buffer not used in the calibration.
Why: Buffer solutions deteriorate over time and verification ensures the calibration curve remains accurate across the measurement range.
Store the electrode in proper storage solution (typically 3M KCl) rather than distilled water to maintain junction electrolyte concentration.
Why: Distilled water causes reference electrolyte dilution and junction clogging, leading to slow response and measurement drift.
Allow 30-60 seconds for readings to stabilize in each sample, especially when moving between solutions of different pH or ionic strength.
Why: Electrode equilibration time ensures accurate readings and prevents measurement errors from unstable electrode potentials.
If readings drift or respond slowly, clean the electrode with appropriate cleaning solution and recalibrate, checking for air bubbles in the reference junction.
Why: Protein deposits, salt buildup, or air bubbles can impede ionic contact and cause measurement instability.
Record buffer lot numbers and expiration dates with calibration data to maintain measurement traceability and identify potential calibration issues.
Why: Buffer quality directly affects calibration accuracy, and documentation enables troubleshooting of anomalous results.
Rinse electrodes thoroughly between samples, especially when measuring samples with different chemical compositions or pH extremes.
Why: Cross-contamination can affect subsequent measurements and potentially damage the electrode through chemical incompatibilities.
Use buffers at the same temperature as test samples when possible, or ensure temperature compensation is functioning correctly.
Why: Temperature differences between calibration and measurement introduce errors even with automatic temperature compensation.
Replace electrode when calibration slope falls outside 85-105% of theoretical (approximately 54-62 mV/pH at 25°C).
Why: Electrode slope degradation indicates glass membrane aging and reduced measurement accuracy across the pH range.
Setup Guide
What’s in the Box
- pH Checker PHB-4 main unit
- pH combination electrode (typical)
- Calibration buffer solutions set (typical)
- Electrode storage solution (typical)
- User manual and quick start guide
- Protective carrying case (typical)
Warranty
ConductScience provides a one-year manufacturer warranty covering defects in materials and workmanship, with technical support available for calibration procedures and troubleshooting.
Compliance
References
Background reading relevant to this product:
What buffer solutions are required for three-point calibration?
Standard pH buffers at 4.00, 7.00, and 10.00 are typically used for three-point calibration, covering the acidic, neutral, and alkaline ranges. The automatic calibration function recognizes these standard values and adjusts electrode slope accordingly.
How often should the pH electrode be replaced?
Electrode lifetime depends on usage frequency and sample types. Typical replacement indicators include slow response time (>60 seconds), inability to calibrate within ±0.02 pH, or slope values outside 85-105% of theoretical. Heavy use may require replacement every 6-12 months.
Can this meter measure pH in non-aqueous or high-ionic-strength solutions?
The glass electrode is optimized for aqueous solutions with moderate ionic strength. Non-aqueous solvents may cause electrode damage, while solutions with very high salt content may show junction potential errors affecting accuracy.
What is the response time for pH measurements?
Response time varies with solution composition and temperature, typically 30-60 seconds for 95% of final reading in well-buffered solutions. Poorly buffered or very pure water may require longer equilibration times.
Does temperature compensation affect both pH and mV readings?
Automatic temperature compensation applies to pH measurements to correct for electrode slope changes and buffer pH shifts with temperature. Millivolt readings show raw electrode potential without temperature correction.
What maintenance is required for optimal performance?
Regular calibration verification, proper electrode storage in storage solution between uses, gentle cleaning of the electrode bulb, and periodic replacement of reference electrolyte (if applicable) maintain measurement accuracy.
Can the meter store calibration data or measurement results?
Consult product datasheet for data storage capabilities. The automatic calibration function retains calibration parameters, but measurement logging features depend on specific model configuration.
Have a question about this product?
Upgrade Options
