Did what I needed. It never seems to go below 30-35 decibels, but then I read somewhere online that the library is between 30-40 decibels, so it seems to be working great. A minor downside is that the instructions say it may need to be recalibrated at some point in the future, but there don't seem to be any instructions on how to do that.
π Accurate Professional Sound Level Calibrator Decibel Meter with 94dB, 104dB, and 114dB Calibration Levels
3 Review
π Professional Red/Black Digital Handheld Sound Level Meter - Automatically Metered with A and C Frequency Weighting for Musicians and Sound Audio Experts - Battery Operated (9V) - Pyle SPL25
5 Review
π VLIKE Digital Audio Decibel Meter: Sound Level Monitor, Noise Measurement 30-130 dB - MAX Data Hold, A/C Mode
8 Review
π REED Instruments R8050 Sound Level Meter: Type 2, 30-100 & 60-130dB with +/-1.4 dB Accuracy
6 Review
π² Johnson RAS-1B Johnny Square: Professional Aluminum Rafter Square, 7'', Silver - Top Quality with 1 Square
8 Review
π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review
Kapro - 353 Professional Ledge-It Try & Mitre Square - For Leveling And Measuring - Features Stainless Steel Blade, Retractable Ledge, And Etched Ruler Markings - 12 Inch
23 Review
β Stainless Steel L-Square, Size 3-Inch x 4-Inch, Zona 37-434
8 Review