1799年,一位意大利科学家Casare Tagliabue在英国伦敦霍尔本建立了该公司。几年后,另一位意大利科学家Louis Pascal Casella加盟该公司并使之成为了新的合伙企业,而Casella公司也因此得名。

        Casella公司早期的产品包括勘探、导航、摄影、气象和医学研究设备。早期的客户包括查尔斯 达尔文和利文斯通博士。19世纪期间,本公司的产品范围继续扩展,在1851年伦敦海德公园水晶宫举办的首届“世界博览会”上,展出了经纬仪和测量设备。随后不久,Casella公司即开发出了首款医用水银温度计,但是此后不久该公司的创新步伐开始减速。





Attribute Type Attribute Value
Sound Range 30 to 121dB
Resolution 0.1dB
Frequency Range 10Hz to 25kHz
DOSE Measurement No
Accuracy Class IEC 651 Type 2, BS5969 Type 2, ANSI S1.4 Type 2A
Battery Type PP3
Display Type LCD


D1405-E & D-1422C Sound Level Meters

Two instruments which satisfy the requirements of International and National IEC 651 Type 2, BS5969 Type 2 and ANSI S1.4 Type 2A standards for both free field and incidence sound level meters. The D-1422C also satisfies the requirements of IEC651 Type 21 for impulse and level meters.
D-1405-E Designed to meet the sound survey requirements of Safety Engineers and Occupational Nurses.
D-1422C Designed for Industrial Safety Officers.
Both instruments feature:

  • Digital indication of A-weighted sound on a LCD
    Standard fast and slow time weighing
    Measures in 2 ranges between 10Hz and 20kHz
    Conditioned a.c. and d.c. outputs from a 3.5mm 3-pole coaxial socket for recording purposes
    Powered by 4 x AAA batteries (not supplied), see Batteries/Chargers section, Book 1

Additional features of the D.1422C

  • A and C weighted sound levels
    Overload condition indication
    Max. hold function
    Battery voltage indicator
Technical specification
Range setting Frequency Display Primary Linearity
  Weighting Range Range IEC651
A LO (low) A 30-100dB 30-90dB
A H (high) A 65-135dB 65-125dB
A LO (low) A 30-100dB 30-86dB
A H (high) A 65-135dB 65-121dB
C LO (low) C 35-100dB 35-86dB
C H (high) C 65-135dB 62-121dB

It is advisable to check these instruments before and after use using the Sound Level Meter Calibrator (stock no. 253-210).
These instruments require a foam windshield for the microphone head for correct operation (stock no. 139-760, available separately). A carrying case which will accommodate either instrument, calibrator and windshield is also available separately.
The lower reading is quoted at 10dB on noise floor, the upper reading allows a crest factor 5.



Attribute Type Attribute Value
Sound Range 30-130 RMSdB
Battery Type AA
Display Type LCD


CEL-240 Sound Level Meter

CEL-240 is an easy to use instrument designed to undertake noise measurements for a variety of applications.
By implementing the latest digital technology, the CEL-240 gives absolute reliability, ensuring the highest levels of accuracy and performance, all housed in a rugged and compact design.
With the graphical display the CEL-240 can display the time-history of noise levels, allowing an easy assessment of the current noise environment.

  • Fully compliant with IEC 61672 2002 class 2; IEC 60651 type 2 (1979)
    30 – 130dB RMS measurement range
    A and C weighted sound levels
    Selectable Fast, slow or impulse time weighting
    2 key operation for intuitive ease of use
    Simultaneous display of instantaneous and maximum sound pressure level measurement
    Bargraph or graphical time-history display of noise levels, allowing an easy assessment of the current noise environment.
    Maximum hold function
    Easy calibration, the CEL-240 automatically recognises the application of a calibrator and with a single key press adjusts the calibration
    USB output to PC
    AC output provided for DAT tape / PC wav file recording or headphone applications.
    dB24 software (available separately) to log the history of noise levels over a desired time period to a PC

Available options and accessories:-

  • CEL-240 sound level instrument kit see stock no. 477-100
    Kit comprises: Hard carry case, CEL-240 sound level meter, CEL 110//2 sound level calibrator, foam windshield, 3 AA alkaline batteries, 1 PP3 battery and instructions on CD-ROM
    CEL 110//2 sound level meter calibrator see stock no. 477-081
    Replacement foam windshield see stock no. 477-093
    dB24 PC logging software see stock no. 477-097
    USB standard A to mini B interface cable see stock no. 418-0166
    Hard carry case see stock no. 477-104
Technical Specification
Applicable Standards IEC 61672-1 2002-5 class 2; IEC 60651 type 2 (1979); ANSI S1.4 Type 2A (1983)
Measurement Range 30 – 130dB RMS
Selectable Ranges 30-100 or 60-130dB
Display 128x128 Mono Graphics LCD, 0.5 seconds update rate.
Total noise floor <33dB(A)
Time weightings Fast, Slow and Impulse
Frequency Weightings A and C
Microphone ½ inch electret capsule
AC output (2.5mm stereo jack socket) Approx 0.5V RMS Full Scale Deflection (FSD) ’A’ weighted output on selected range. Minimum load impedance 22kΩ.
Dimensions and weight 72 x 212 x 31mm: 245g inc batteries
Batteries 3 off AA alkaline (supplied) or rechargeable NiMH cells
External Power 5V via USB 2.0 mini socket type B
Tripod Mount ¼ inch Whitworth socket

It is advisable to check the instrument before and after use using the CEL 110//2 sound level meter calibrator see stock no. 477-081


3 AA alkaline batteries, windshield, carry strap and manual on CD-ROM