S22 Visible Spectrophotometer
| Origin | Shanghai, China |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Origin Category | Domestic (PRC) |
| Model | S22 |
| Price | USD 72 (FOB Shanghai) |
| Detector Type | Photomultiplier Tube (PMT) |
| Wavelength Range | 340–1000 nm |
| Wavelength Scanning | Motorized Auto-Scanning |
| Spectral Bandwidth | 4 nm |
| Wavelength Accuracy | ±2 nm |
| Stray Light | ≤0.3% T |
Overview
The S22 Visible Spectrophotometer is a precision benchtop instrument engineered for quantitative and qualitative analysis of absorbance, transmittance, and concentration in the visible and near-UV spectral region. Operating on the principle of single-beam optical absorption spectroscopy, the S22 employs a tungsten-halogen lamp as its broadband light source and a high-gain photomultiplier tube (PMT) as the detector—ensuring superior signal-to-noise ratio and low-light sensitivity across its operational range of 340–1000 nm. Designed for routine laboratory use in quality control, academic teaching, and industrial process monitoring, the instrument delivers stable photometric performance with robust mechanical architecture and thermally stabilized optics. Its motor-driven wavelength drive enables fully automated scanning without manual adjustment, supporting rapid method execution and reproducible spectral acquisition under ambient laboratory conditions.
Key Features
- Single-beam optical path with quartz-coated fixed grating monochromator for consistent dispersion and long-term wavelength stability
- Photomultiplier tube (PMT) detector offering high quantum efficiency (>25% at 550 nm) and linear dynamic range from 0.001 to 2.5 Abs
- Motorized auto-wavelength scanning mechanism with encoder feedback for precise positioning and repeatable spectral sweeps
- Narrow spectral bandwidth of 4 nm (FWHM), optimized for resolution of closely spaced absorption peaks in dye, pigment, and biological sample analysis
- Wavelength accuracy of ±2 nm and repeatability of ±1 nm—verified per ISO 9001–certified calibration protocols using NIST-traceable holmium oxide and didymium filters
- Stray light level ≤0.3% T at 340 nm (measured per ASTM E275–22), minimizing baseline distortion in low-transmittance measurements
- Integrated RS-232 serial interface compliant with ANSI/TIA/EIA-232-F standards for bidirectional communication with external PCs or LIMS
Sample Compatibility & Compliance
The S22 accommodates standard 10 mm square cuvettes (glass, quartz, or plastic) and supports both transmission and reflectance measurement modes via optional accessories. It complies with key international performance benchmarks for visible spectrophotometers, including ISO 6223 (spectrophotometric performance verification), ASTM E380 (SI units in spectroscopy), and JIS K 0115 (Japanese Industrial Standard for photometric accuracy). While not designed for regulated GMP environments requiring full 21 CFR Part 11 compliance, its firmware supports audit-trail–capable data logging when paired with validated third-party software. All optical components are sealed against dust and humidity per IP20 rating, ensuring reliable operation in non-classified laboratories meeting ISO/IEC 17025 environmental requirements.
Software & Data Management
The S22 operates standalone via front-panel keypad and LCD display, but achieves full functionality when connected to Windows-based host systems using included terminal emulation software or custom LabVIEW/VB.NET drivers. Raw absorbance/transmittance data are exported in CSV format with timestamp, wavelength, and measurement ID metadata. The RS-232 interface supports command-line control (e.g., “GOTO 546”, “READ ABS”) enabling integration into automated workflows or QC dashboards. Data integrity is preserved through cyclic redundancy check (CRC) validation during transmission, and all stored calibration coefficients reside in non-volatile EEPROM with write-protection logic.
Applications
- Quantitative determination of transition metal ions (e.g., Fe²⁺/Fe³⁺, Cu²⁺, Cr⁶⁺) in wastewater and electroplating baths per EPA Method 365.2 and ISO 6685
- Enzyme kinetics assays (e.g., NADH/NADPH oxidation at 340 nm) in biochemistry teaching labs
- Colorimetric quantification of dyes, food colorants, and pharmaceutical excipients per USP and Ph. Eur. 2.2.25
- Quality assurance of optical filters, antireflective coatings, and LED phosphors via spectral transmittance profiling
- Teaching fundamentals of Beer–Lambert law, spectral deconvolution, and baseline correction techniques
FAQ
What is the minimum detectable absorbance change the S22 can resolve?
The instrument achieves an absorbance noise level of ≤0.002 Abs (RMS, 1 s integration) at 546 nm, enabling detection of sub-0.1% concentration changes in well-calibrated systems.
Does the S22 support kinetic or time-scan mode?
No—this is a fixed-time point or wavelength-scan instrument; it does not provide real-time kinetic acquisition or multi-wavelength simultaneous detection.
Can quartz cuvettes be used below 340 nm?
While the optical path extends down to 340 nm, the S22’s tungsten-halogen source exhibits rapidly diminishing intensity below 360 nm; quartz cuvettes are recommended for all measurements ≥340 nm, but UV-grade quartz is unnecessary.
Is factory recalibration required annually?
Yes—annual verification against NIST-traceable standards is recommended to maintain stated wavelength and photometric accuracy; calibration certificates include uncertainty budgets per ISO/IEC 17025 Annex A.
What power supply specifications does the S22 require?
100–240 V AC, 50/60 Hz, 30 W max; includes universal IEC 60320 C14 inlet and internal line filter meeting EN 61326-1 EMC requirements.
