The manual dedicates several pages to wavelength accuracy and spectrum scanning. In practice, many users set a single wavelength (e.g., 254 nm) and forget about it.
The RESPONSE setting controls the digital filter applied to the output signal.
Turn on the main power switch located on the bottom left of the detector front panel.
If sensitivity decreases or noise increases, flush the cell with appropriate solvents (e.g., IPA or mobile phase).
[Safety Warning] Turn off the main power and unplug the unit. Allow the lamp to cool for 30 minutes before touching it to prevent severe burns. shimadzu spd20a user manual better
Even with a solid manual, troubleshooting can be tricky. Here are faster solutions for common problems based on user experience. Probable Cause Better Solution Air bubble in cell Purge the cell at high flow rate. Check pump seals. Drifting Baseline Insufficient warm-up Allow at least 60 min for lamp stability. Low Energy Error D₂ Lamp aging Replace D₂ lamp; check lamp energy via software. Peak Splitting/Broadening Cell contamination Wash flow cell with 100% IPA or nitric acid (if needed). Low Sensitivity Incorrect wavelength Verify wavelength of maximum absorption. 5. Utilizing the Service Manual for Advanced Users
A consistent startup procedure is essential for reliable results. Follow these steps daily:
Periodically wash the flow cell with a solvent that dissolves your analytes (e.g., 50:50 methanol/water or 100% isopropanol) to remove contaminants.
Pull the old lamp straight out. (skin oils cause hot spots and premature failure; use lint-free gloves). The manual dedicates several pages to wavelength accuracy
Follow this streamlined protocol to power up, initialize, and prepare your SPD-20A for analysis. Step 1: Power Initialization
For lab managers and service technicians, the Shimadzu SPD-20A Service Manual (70 pages) is invaluable. It covers: Optical system adjustment (mirrors and lenses). Signal processing circuits and board repairs. Detector unit calibration procedures.
Proactive maintenance extends the lifespan of your optics and prevents costly system downtime. Deuterium ( D2cap D sub 2 ) Lamp Replacement D2cap D sub 2
The 20AV enables simultaneous deuterium and tungsten lamp operation for high-sensitivity tracking across the entire ultraviolet-visible range. Turn on the main power switch located on
Many free PDFs online are poor scans. Instead, go directly to:
Ensure the PEEK fittings are tight but not overtightened to avoid damaging the cell window. 4. Better Troubleshooting: Solving Common SPD-20A Issues
When your chromatography goes wrong, use this prioritized guide to isolate the issue immediately. Probable Cause Action Item Blown fuse or faulty power cord.