Measure Noise With A Sound Level Meter (Sound Level Meter Test)

If you are concerned with the topic of noise and are always looking for ways to ensure more peace and quiet at home, then a sound level meter could be of great value to you.

Learn more about these helpful devices in this article. You can also find our sound level meter test here.

What is a sound level meter?

A sound level meter is a device with which sound pressure levels can be measured. The sound pressure level is a logarithmic quantity used to describe the strength of a sound event.

You can find more information about sound pressure levels at Wikipedia .

As a rule, measurements are taken with an integrated measurement microphone with an omnidirectional characteristic. After the measurement, the level in decibels (dB) can be read on a display.

A sound level meter essentially consists of the following components:

• Measuring microphone with omnidirectional characteristics
• Preamplifier
• Evaluation unit
• Display

Further names for such a device are decibel meter, db meter, decibel meter, sound level meter, sound meter, noise meter or volume meter.

Sound level meter possible uses

A sound level meter is often used to monitor compliance with noise protection regulations and to measure noise hazards for occupational safety.

But there are also a number of useful applications in your own four walls.

Would you like to put a soundproofing on the wall to the neighbor because he is too loud for you? Then you could take measurements before and after with a sound level meter to document the success of your measures.

With a sound level meter you can also find out whether the sound insulation curtain or the window sound insulation is actually showing its effect.

Is the new, quiet hair dryer really quieter than the old model? And have the quiet kettle and the quiet vacuum cleaner proven themselves ?

Find out by taking before and after measurements with a sound level meter.

In addition, there are of course many other scenarios in which a noise meter can be used.

For example, you might want to document exactly how much noise from your neighbor enters your apartment. This can be important if you want to present a noise report to your landlord.

Which sound level meter to buy?

If you take a look at the sound level meter market, you will quickly notice that there is a large selection of devices on offer. That makes it all the more difficult to choose. And you might ask: which sound level meter should I buy?

First of all, we focused on the affordable devices and studied their customer reviews on Amazon.

We noticed that with some devices in the 20 euro price range, a certain point of criticism kept cropping up. Namely that the devices are too imprecise. Sometimes there was even talk of some devices showing utopian high values ​​when they were switched on in a quiet room.

We didn’t want to risk that, so we opted for a slightly more expensive model that also comes from a German manufacturer. We bought the TROTEC SL300 sound level meter.

The TROTEC sound level meter SL300 in the test

First of all, it should be said that we are not professionals when it comes to determining sound pressure levels and only use the device for domestic use.

Nevertheless, we have been dealing with the subject of “measuring volume” for some time and have already had some experience with it. A sound level meter test is therefore a good idea .

Delivery and packaging

When the TROTEC SL300 sound level meter arrived, we were positively surprised.

Because the sound level meter came well packaged in a practical plastic box with neatly cut recesses for the device itself and a 9 V block battery. The battery is already included so that the device is immediately ready for use.

This box is not only good for transport, but also for storing the measuring device.

Sound level meter TROTEC SL300 Design and processing

Sure, with a sound level meter, design is certainly not the focus. Nevertheless, the product design is not entirely unimportant.

The SL300 has a housing made of yellow plastic and black rubber inserts on the right, left and bottom. These inserts ensure that the device is comfortable and non-slip in the hand.

On the front is the easy to read and illuminated display and a total of 6 rubber buttons, all of which are labeled.

A mini instruction manual is printed under these keys, which describes the key combinations for Record, Read and Erase Memory. That is also practical.

On the back is the flap for the battery, which is secured with a cross screw.

There is also a 1/4 inch tripod thread here. This is definitely worth mentioning, as it makes it easy to screw the device onto a tripod.

For our test we screwed the TROTEC SL300 onto our small gorilla tripod ( available here at Amazon * ), which we normally use for a camera. That worked perfectly.

The microphone, which is equipped with a removable windshield, sits on top of the device.

Overall, the device makes a well-made and stable impression.

Operation and handling

The operation of the TROTEC SL300 sound level meter is very easy. A total of 6 buttons are available for this.

On / Off button

The device is switched on and off with the on / off button. You can also use this button to turn on the backlight.

A / C button

This key is used to select the frequency curves dB (A) or dB (C). So far we have only used dB (A).

This button can also be used to set the date and time.

Hold button

A value that has just been measured can be frozen with the Hold button. In addition, this button can also be used to delete the data memory when switching on.

Level / Rec button

The level key is used to set the individual measuring ranges. The following measuring ranges are available:

• 1: 30 – 80 db (Lo)
• 2: 50 – 100 db (Med)
• 3: 80 – 130 db (Hi)
• 4: 30-180 db (car)

This key can also be used to store a value previously frozen with the Hold key in the data memory.

Max / Min button

With the Max / Min the lowest or highest measured value can be recorded. This value is held until a lower or higher value is measured.

That’s pretty handy. For example, we usually want to measure the highest value and therefore measure with the abbreviation “MAX” in the display. So the highest value is always shown in the display.

F / S button

With the F / S button (Fast / Slow) the sampling rate or the reaction time can be set. The following settings are possible here:

• FAST – approx. 1 x every 125 mS
• SLOW – approx. 1 x per second

At first glance, these 6 buttons may seem a little complicated to one or the other. But they are not at all. The controls are out after a short time and are easy to do.

The device starts measuring immediately after pressing the on / off button.

TROTEC sound level meter SL300 properties at a glance

The following table gives you an overview of the most important properties of the TROTEC sound level meter SL300:

Own measurements with the sound level meter

Of course, we also took some measurements in our apartment. We took all measurements approx. 1 meter from the noise source and recorded the loudest value.

decibel	Sound source
74	toilet flush
63	Let the water run in the sink
63	water heater
70	vacuum cleaner
33	Quiet room
44	Gas stove 2 plates
78	hairdryer
70	Electric mixer (kitchen)

Conclusion on the TROTEC sound level meter SL300

How did our sound level meter test go? Well, we are absolutely satisfied with the TROTEC SL300 sound level meter. The device is well made, lies comfortably in the hand and is easy to use.

The measuring device also offers some useful functions and comes with a practical tripod thread. What more could you want for household use?

Cheap alternative – sound level meter Meterk

If you don’t want to spend so much money straight away, then you can look at the Meterk sound level meter as an inexpensive alternative to the TROTEC sound level meter SL300.

Sound level meter Meterk properties at a glance

The following table gives you an overview of the most important properties of the Meterk sound level meter:

Class 1 or Class 2?

Sound level meters are offered in two different classes, namely class 1 and class 2 . These two classes differ in terms of the accuracy of the measurement.

Class 2 sound level meters measure a narrower frequency spectrum with a higher tolerance than class 1 devices. In addition, they are significantly cheaper to buy. For household use, however, class 2 devices are usually completely sufficient.

Purchase criteria for a sound level meter

Do you want to buy a sound level meter? Then it would certainly be advisable to pay attention to some purchase criteria before buying.

From our point of view, these would essentially be the following points:

Measuring range

The measuring range specifies the range in which the measuring device can measure volume. The TROTEC sound level meter SL300, for example, has a measuring range of 30 – 130 dB (A).

Sound below 30 and over 130 dB (A) can no longer be measured with this device. Sound sources such as rustling leaves, breathing, snowfall, the ticking of a clock and whispering are below this measurement limit.

Sound sources such as an airplane taking off, a car race, a shot from a rifle, a blacksmith’s hammer, a rocket launch or even a gun bang are above this range of 130 dB (A). The device cannot measure these sound sources either.

Everything in between can be measured with the device.

In the following table you can find examples of the volume of different sound sources. Note, however, that these are only rough estimates.

Of course, it always depends on the distance from the sound source the measuring device measures. Such measurements are often carried out from a distance of 1 meter.

decibel	Sound source
10	Breathing, snowfall, the ticking of a clock
20th	Mosquito, rustling leaves
30th	light wind, whispering, quiet room, fan, ticking of a clock
40	light rain, quiet conversation, quiet music, birdsong
50	Fridge, normal conversation, moderate rain
60	TV at room volume
70	Vacuum cleaner, hair dryer, loud conversations
80	Main thoroughfare, piano, chainsaw, motorcycle
90	Orchestra, hand grinder
100	Jackhammer, circular saw, discotheque, headphone music
110	Rock concert, drums, car horn
120	Chainsaw, thunderstorm
130	siren
140	Taking off plane, car racing, shot from rifle
150	Blacksmith hammer, rocket launch
160	Slap on the ear, gun blast

accuracy

The accuracy specifies which deviations the measuring device may have during its measurement. The accuracy is, among other things, responsible for whether the device is a class 1 or class 2 sound level meter. Class 1 devices usually have a lower tolerance.

Frequency range

The frequency range indicates in which range the device can measure. Our TROTEC sound level meter SL300 can measure, for example, in the range 31.5 Hz – 8 kHz. Class 1 devices usually have a wider frequency spectrum than class 2 devices.

resolution

The resolution indicates how the sound level is displayed. For example, units or decimal places are possible here. Most of the time, a tenth of a decibel is sufficient.

Our sound level meter has a resolution of 0.1 dB, so the sound level is also displayed here to a tenth of a decibel.

Display

The display of the device should also be an important purchase criterion. Because of course it is important that the display is always easy to read.

So you should make sure that the values ​​are displayed in a comfortable size and that the display is illuminated if you want to measure in the dark.

handling

Of course, it is also important that you get along well with the respective device and that it is easy to use. In addition, the operating instructions should be easy to understand. Ideally, the basic functions of the device can even be operated intuitively without a user manual.

More functions

Before buying, you should definitely take a look at the functions and features of the respective device. Functions such as memory, recording (e.g. sound level meter with recording), tripod socket, software or other functions can – depending on the requirements – be important.

Sound level meter apps

Sound level meter apps can also be used to determine sound pressure levels. This means that it is then possible to measure the sound level with the smartphone.

The following two apps are suitable for this purpose:

However, we do not know exactly how such apps can measure. We also do not know whether the accuracy of these measurement results depends on the smartphone used.

Sound level meter versus sound measurement (sound meter) app

But we wanted to test to what extent the measurements of such an app differ from the measurements of our sound level meter.

For this comparison, we placed our sound level meter right next to our smartphone with the “Sound Meter” app on a cardboard elevation so that the devices are not directly on the tabletop.

With our TROTEC sound level meter SL300, we have set the measuring range Level 1 (30 – 80 dB). We left the Sound Meter app as it is.

This is worth mentioning because you can still perform a calibration within the app, where you can simply add values ​​with the plus or minus button.

We took several measurements in a row, all of which differ only slightly due to the noise in the room. However, the difference was almost identical for each measurement.

We also put the smartphone down once so that the microphone was pointing downwards and once so that the microphone was pointing upwards. We wanted to rule out the possibility that the position of the device could cause major deviations. But that was not the case – the deviations were only minor.

You can see the results of our measurements on the two pictures below:

As you can see in the pictures, the deviations are considerable.

Since we measured in a quiet room, in which, according to the usual tables, normally around 30 decibels are measured, the sound level meter seems to measure much more precisely than the non-calibrated app.

With the help of the sound level meter, we could of course calibrate the Sound Meter app in order to be able to achieve more precise results with the app in the future.

Conclusion

We have already measured and recorded a number of interesting values ​​with our sound level meter.

It is quite informative if you can assign a specific value to the noise of a device or other noise sources.

We find such a sound level meter to be extremely helpful, especially when you are busy creating the quietest possible environment.