Environmental Monitoring Equipment & Supplies • Sales, Rental & Service by Enviro-Equipment — Charlotte, North Carolina USA

  • Type 1 ANSI Sound Level Meter, 20-140 dB measurement range.
  • Octave (16 Hz to 16 kHz) and 1/3 octave (12.5 Hz to 20 kHz) band measurements for Lmx and Leq with selected frequency and time weightings.
  • Broadband measurement in periodic or cumulative mode for summary data, profile mode for individual noise captures at user defined interval.
  • Software included for data download and generating reports and graphs.
  • Field calibrator and annual factory calibration certificate included.
CEL-633-1 Casella CEL 633C Daily Rate $120.00
CEL-633-WK Casella CEL 633C Weekly Rate $375.00
CEL-633-MO Casella CEL 633C Monthly Rate $1,115.00

The CEL-633C series is an easy to use instrument designed to undertake the measurement requirements of workplace and environmental noise. It also complies with the latest IEC and ANSI international standards for sound level meters. Just switch on the instrument, auto-calibrate and start measuring with one of the predefined views. Regardless of the view selected, all data is measured and stored simultaneously so no mistakes can be made.

By implementing the latest digital technology, the meter has a single measurement range so no range adjustment is required, ensuring the highest levels of performance with all noise sources. The CEL-633C can be used for environmental and/or occupational noise with the availability of frequency analysis and advance functions such as data markers, timers and logging of time history data. Even with such advanced functionality, the CEL-633C Series remains very simple to use.

Audio recording is a standard feature of the CEL-633C, all models having a voice notes capability. This allows you to speak into the microphone before or after a measurement in order to annotate the result, so you don't need to write things down. Data can also be 'marked' during a measurement to signify either an anomalous or significant event and audio is also recorded for later noise source identification. If the instrument is used for unattended measurements, audio recording can be triggered by a condition such as a given level being exceeded for a period of time. In this case additional data will be collected along with the audio. This can be especially useful where the noise source of interest is transient.

When the unit is calibrated with the CEL-120 calibrator, the calibration dates and times are stored and downloaded to Casella insight software, validating the accuracy of measurements. Average, peak, and octave band measurements are performed at the same time, so only one measurement needs to be made for all workplace noise applications. Data can be marked to signify any significant events, the data from which can be removed afterwards in insight software.

Items Included:
  • CEL-633C Octave Band Analyzer
  • Acoustic Calibrator
  • Factory Calibration Certificates
  • Wind Screen
  • AC Power Adapter
  • Hard Carrying Case
  • Casella Insight Software
  • USB Data Cable
  • Spare Batteries
  • User Manual


ANSI S1.4 & S1.43, IEC 61672-1 2002-5

Frequency filters comply with

ANSI S1.11 and IEC 61260

Microphone type

½" Free field Electret microphone & preamplifier Type 1 or Type 2 on a removable CEL-495 preamplifier

Reference Conditions

68°F (20°C) air temperature, 65% Relative Humidity, 1013 mbar (101.325 kPa) atmospheric pressure.

Operating Temperature Range

14 to 122°F (-10 to 50°C) (Class 1) 32 to 104°F (0 to 40°C) (Class 2)

Effect of Humidity

Less than ±0.5dB over the range 30 to 90% RH (non-condensing), rel. to value at ref. conditions

Operating pressure range

650 to 1080 mbar (65 to 108 kPa)


3 x AA Alkaline or NiMH rechargeable types

Battery Life

Up to 12 hours without backlight

Dimensions w x h x d

2.8 x 10.5 x 1.2 in (71.5x 267.0x 31.0mm) including preamplifier and microphone

Weight including batteries

10.1 oz (< 291g)

Tripod socket for fixed measurements

Yes via standard camera thread (1/4" size)

Operator controls

8 buttons for power On/Off + 2 x context sensitive menu selection + 4 navigation + confirm selection

Total measurement range

20 to 140 dB

Dynamic range on single measurement span

120 dB

Noise floor (A weighted dB)

< 20 (Class 1), < 25 (Class 2)

Frequency weightings

Simultaneous A, C & Z (unweighted)

Time weightings

Simultaneous Slow, Fast and Impulse

Displayed parameters available

Lp, Lmx, Lmn, Lpk Leq, LIeq, LDOD, Lavg, LAE, Ltm3, Ltm5 LDN, LDEN, CNEL, 5 x LN%

Narrow band real time measurements

(C version) 33 third octave bands 12.5 Hz to 20 kHz with cursor readout plus A & C & Z broad band levels

Display of octave and third octave band levels

Graphical spectrum including broad band values & With listing of individual band levels in tabular format

Measurements in octave (& 1/3) band mode include

Lmx and Leq with selected freq and time weightings

Display type

240 x 320 full color dot matrix LCD digital including real-time analog bar graph scale

Data storage for time history logging

999 run maximum memory, long term recording is separated into "24 hr days" that can be recombined in Insight software for later analysis and review

Timed interval for regular data storage

1 sec to 1 hour in 13 fixed intervals for Periods 1 sec to 30 mins for Profiles

Event capture with audio recording

User selectable trigger level 40 – 140 db in 1 dB steps Wav file stored at hi, med or lo resolution

Displayed time span for time history graph

Last 60 seconds

Signal detected when calibrator placed over microphone at 1 kHz frequency

Calibration level set to 114.0 or 94.0 dB With +/-1 dB span and 0.1 dB resolution by user

External power option (12 Vdc) or via USB 5V line

Yes via universal CEL-PC18 unit

Analog outputs

AC (and optional DC) via 2.5 mm jack socket

AC output characteristics

Approx 0.85V RMS FSD output on selected sound level measurement range. Minimum load impedance 22kΩ.

DC output characteristics

0 to 1.3V DC for FSD on selected range.

Digital output of stored result sets

Via USB 2.0 mini B connector to Casella Insight program