Testo Sound Level Calibrator – 94/114 dB, 1000 Hz, IEC 60942 Class 2, Compatible with ½ and 1 inch Microphones (0554 0452)

The Testo sound level calibrator (product code 0554 0452) is an acoustic calibrator that produces reference sound pressures of 94 dB and 114 dB at a frequency of 1000 Hz for on-site calibration and checking of sound level meters (decibel meters). It operates with ±0.5 dB accuracy in accordance with IEC 60942 Class 2; in addition to the Testo 816-1 and Testo 815 sound level meters, it can also be used with instruments from other manufacturers with ½ and 1 inch microphones.

On-Site Calibration of the Sound Level Meter

The calibrator is fitted onto the measuring instrument's microphone with a twisting motion; for ½ inch microphones the supplied adapter is used, and when the adapter is removed a 1 inch microphone is inserted directly. The frequency and time weighting normally used are selected on the measuring instrument, the calibrator is set to the 94 dB position, and the value on the display is compared with the target value corrected for altitude; if there is a deviation, it is corrected with the instrument's adjustment screw. A check is then carried out in the 114 dB position.

The LED on the front panel shows that the unit is operating and indicates battery status: when the battery voltage is insufficient, the LED changes from green to red and the calibrator gives no signal. It runs for approx. 40 hours on a 9 V block battery; its compact body is easily carried in a field case.

Technical Specifications (Official Testo Information)

• Brand / Model: Testo sound level calibrator · product code 0554 0452
• Sound Pressure Level: 94 dB / 114 dB (under reference conditions, selectable) · accuracy ±0.5 dB (IEC 60942 Class 2)
• Frequency: 1000 Hz ±2% · distortion < 3%
• Reference Conditions: +23 °C · 50% relative humidity · 1013 hPa
• Operating Conditions: 0 … +40 °C · 10 … 90% relative humidity · 650 … 1080 hPa (up to 2000 m above sea level)
• Influence Coefficients: pressure 0.005 dB/hPa · temperature 0.005 dB/°C · humidity 0.005 dB/%RH
• Microphone Compatibility: ½ inch (with adapter) and 1 inch microphones
• Power Supply: 9 V block battery (6F22) · battery life approx. 40 hours · continuous battery status monitoring via LED
• Storage Conditions: −10 … +50 °C · 0 … 70% relative humidity
• Dimensions / Weight: 113 × 63 × 44 mm · approx. 170 g (including battery)

Scope of Delivery

• Testo sound level calibrator (with ½ inch microphone adapter fitted)

Technician Recommendations

• Apply the altitude correction: subtract from the 94 dB target value according to altitude — 0 … 250 m: 0.0 dB · 250 … 850 m: −0.1 dB · 850 … 1450 m: −0.2 dB · 1450 … 2000 m: −0.3 dB (for example, target 93.9 dB at 500 m).
• Check with 114 dB: after adjusting at 94 dB, measure again in the 114 dB position; if the deviation exceeds ±0.2 dB and cannot be eliminated by adjustment, send the instrument for service.
• Seat the calibrator fully: fit it onto the microphone with a twisting motion so that no gap remains; an air gap lowers the reading.
• Calibrate with the usual settings: select on the measuring instrument the frequency (A/C) and time (fast/slow) weighting you use in the field and calibrate with those settings.
• Replace the battery if the LED is red: with a low battery the calibrator gives no signal; keep a spare 9 V battery in your field case.

Technical document: Testo sound level calibrator user manual (PDF, German/English)