...And a Class 2 is accurate to within two dB. But both of these are as measured at 1kHz, not across the audio band.
I have a Quest Type 2 that I bought new in 1996 for business (noise consultant) and had it certified every year and it was never more than 0.18 dB from the standard so a Type 1 wouldn’t necessarily be any closer.
Know that in addition to the meter, you will also want a calibrator, and if you intend to keep your meter and calibrator factory calibrated to the standard, the last time I had mine calibrated (am now retired) was ~10 years ago and it cost >$350 + shipping both ways. Actually, the meter, the mic, and the calibrator are all done separately. This was a yearly requirement when I was in business.
B&K makes the best units, but Larson Davis and Quest are also very good and less $$$.
BTW, you could buy a used Behringer 2496, 61-band RTA with a microphone or an REW set-up for less money than having your meter factory calibrated/certified just once.
