CR:270 Series Sound Level Meters
The CR:270 series is a range of instruments designed for the measurement of industrial and environmental noise levels. The main application for the instruments is to measure noise levels for compliance with Noise at Work regulations.
The instrument are capable of measuring L eq (Average Noise Level) and Peak levels, with the parameters being calculated simultaneously. The CR:272 and CR:271 instruments provide the measurement of both A and C weighted levels, allowing the prescription of hearing defenders using the HML method. The CR:274 and CR:273 instruments have the addition of internal octave band filters and dB(Lin), which allow the use of the Octave Band method for the accurate selection of hearing protection
The main physical difference between the units is in the microphone and preamplifier assembly. The Type 1 CR:271 and CR:273 units are supplied with a removable preamplifier as standard, allowing the instrument to be used with extension cables.
The AC and DC outputs allow the CR:270 series to be used as a front end for additional measurements systems and data recording applications.
A range of accessories is available for the CR:270 instruments including windshields and carrying cases. The instrument is also available as a measurement kit
Specifications
| Standardisation | CR:272 | Type 2 of IEC 60651 & IEC 60804 |
| CR:271 | Type 1 of IEC 60651 & IEC 60804 | |
| CR:274 | Type 2 of IEC 60651 & IEC 60804, Octave Band Filters to IEC 61260 | |
| CR:273 | Type 1 of IEC 60651 & IEC 60804, Octave Band Filters to IEC 61260 | |
| Measurement Range | CR:272 | 32 dB(A) to 140dB(A), 50dB(C) to 140dB(C) |
| CR:271 | 27 dB(A) to 140dB(A), 50dB(C) to 140dB(C) | |
| CR:274 | 32 dB(A) to 140dB(A), 50dB(C) to 140dB(C) | |
| CR:273 | 27 dB(A) to 140dB(A), 50dB(C) to 140dB(C) | |
| All instruments | 60dB(C) to 143dB(C) Peak | |
| Frequency Weighting | CR:272 & CR:271 | dB(A) & dB(C) to IEC 60651 |
| CR:274 & CR:273 | dB(A) and dB(Lin), 10 Octave Bands | |
| Time Weighting | All Instruments | Fast, Slow, Impluse to IEC 60651 |
| Display | 3 1/2 Digit LCD with Overload & Battery | |
| Outputs | AC and Log DC | |
| Size & Weight | CR:272 & CR:274 | 255mm x 75mm x 25mm, 380 gms |
| CR:271 & CR:273 | 325mm x 75mm x 25mm, 430 gms | |
| Power | All Instruments | 2 x 6LR61 (9v PP3) |
- Links:
- Product Datasheets: CR:272 Sound Level Meter Product Datasheet (PDF)
- Product Datasheets: CR:271 Sound Level Meter Product Datasheet (PDF)