Troubleshooting? Here are a few tips:

Nozzle Sizing:

The easiest way to size a nozzle is to use the same size you are already using. For example, if you are using a #6 (3/8") nozzle, use a #6 (3/8") Ninja nozzle. That said, sometimes operators are blasting in conditions with very low PSI or very high PSI and may need to size up or down depending upon their setup. Please see the chart below to determine what nozzle is best for you. 

ninja nozzle sizing chart

Pro Tip - Measuring noise correctly can be difficult even for experienced technicians who do this for a living. Read our tips on how to compare Blast Ninja™ vs other nozzles.

Isolate Nozzle Noise:

If you are testing in a contained area such as a blast room this is particularly important as sound is generated from multiple sources and bounces off of objects - creating an unreliable setup for taking sound level measurements.

  1. Check your Setup: Measure your noise with your compressor and blowers running, but without operating the nozzle. If your noise levels are high, check your compressor and blower setup as these can create large amounts of noise. You want them to be as far away from the blast operator as possible. 
  2. Start with Open Air: Start by blasting in the open air (not onto a piece you need to clean). Your abrasive media bounces off of objects generating noise. Depending upon what you are blasting, the sound levels can exceed the nozzle noise. 
  3. Blast a Dense Object: If you want to blast an object, something solid like a heavy anvil will be your best bet because of its high density and even distribution of noise energy.

Your Noise Measurement Setup Matters:

Follow OSHA guidance on how to measure noise exposure to the blast operator: 1910.95 App G - Monitoring noise levels non-mandatory informational appendix

"With a dosimeter, the microphone is generally located on the shoulder and remains in that position for the entire workday. With a sound level meter, the microphone is stationed near the employee's head, and the instrument is usually held by an individual who follows the employee as he or she moves about." 

The further away you get from the nozzle itself, the more surrounding noise can interfere with the measurements. 

ninja sound meter setup

Measure Ambient Noise:

Take a noise reading in the blast room without running the nozzle, but with the compressor on. This give you a baseline of the compressor noise which is sometimes louder than the nozzle.

Check Your Sound Meter:

If you have an EH&S or HSE department they have a high-quality Class 1 sound meter which is recommended for noise measurements to quantify noise level reductions. However, if you do not have access to a meter, pay attention to the quality of the meter as we have noticed that lower end sound meters are unable to reliably measure higher levels of noise levels. 

Make sure to calibrate your sound meter before taking measurements. If you need to use your measurements in any planning or legal scenario this is vital. This is done using an acoustic calibrator and needs to be done before and after each series of measurements you do. For example, if you are taking several measurements in a factory during the whole day you would be advised to carry out field calibration when you start and then again if you have a break for lunch, and then again when you restart and stop at the end of the day, and so on. 

Compare Noise Readings vs Other Nozzles:

The Blast Ninja™ nozzle should be compared with a similar sized venturi nozzle. In general, larger diameter nozzles will produce more noise compared with smaller ones. If you are using a #6 venturi nozzle, below are a few commonly found nozzles that serve as good comparisons:

- Kennametal TLVE

- Clemco CSD

Corner Cases:

We have not tested the Blast Ninja™ nozzle with the following setups and therefore cannot give you direction on how well it will work. We welcome your feedback so we can improve our nozzle design to accommodate as many setups and situations as possible.

  • Wet blasting
  • Sponge blasting
  • Vapor blasting
  • Dry ice blasting