Yes. The Ranos dB is calibrated before shipping and comes with a factory calibration. Regular sound level calibrations can be done with a Calibrator. In Dashboard+, measurement deviations can be corrected.
The Ranos dB frequency response is calibrated at the factory to be within +/- 2 db, at the moment this can only be done by DSS. You can perform periodical sensitivity calibration yourself, using standard calibrator mounted to the microphone producing a 1kHz tone at 94 or 114 dB(A/C). The sensitivity offset can be adjusted in the settings of the sensor in your dashboard.
On Wikipedia you will find more information about the meaning of different sound measurements and weighting.
Does the microphone have a standard diameter, so that I can calibrate it with a normal portable sound calibrator?
Yes, the diameter of the microphone is 1/2″ and suitable for a normal portable sound calibrator.
Yes, the calculation is completely separate.
Yes, both are one single sample of the measurement interval.
We do not buffer measurement data locally on the sound sensor. Due to the maximum duty cycle, we can only transmit once every minute.
Every message sent contains the maximum amount of data. As a consequence, there wouldn’t be enough bandwidth left to send buffered data once the connection is restored.
The LoRa network is not suitable for sending large data packages such as WAV. That is why we only send the sound pressure/level in decibels.
We have, however, developed a technical blueprint allowing us to send audio fragments via LTE-M. Sign up for our newsletter to stay up to date.
This depends on the sound source(s) of interest and the situation. Sound level decreases by 6 dB for each doubling of distance. For example, if a sound source measures 110 dB at 1 meter, then at 2 meters you will measure 104 db, at 4 meters 98 dB etc.
In a completely quiet environment, you would be able to increase the measurement distance until the noise floor of the sound level meter (which is 33 dB) is louder than the sound produced by the sound source of interest.
For a sound source that produces a measured sound level of 110 dB at 1 meter, that would mean it would be measurable from a distance of over 4 kilometers (not taking into account the influence of environmental conditions).
In reality, however, we have to deal with many other factors, such as objects between a sound source of interest and the sound level meter, other nearby sound sources that might be louder than the sound source of interest due to the smaller distance, etc.
Nothing, you just need the (Android) app and under ‘Support’ you will find all the information about the payload description, cloud dashboard endpoint and how to connect the sound sensor to any LoRa network.
Yes, body and microphone are 100% waterproof and weatherproof.
1. Check if the top cable glands are tightened (microphone and solar panel). Hold the base of the gland with an adjustable spanner or pliers to prevent the nut on the inside from coming loose. Tighten the top compression nut.
2. Check if the vents are tightened (these look like hexagonal bolts). Tighten these vents as much as possible by hand, or tighten them carefully with tools using little force. This is in order to prevent damage to the silicone seal.
3. Check if the PCB shows signs of corrosion. Corrosion marks are white/greenish and can be found on and around soldered seams or other bare metal parts.
4. Check if the foam lid seal is still in place and free of damage.
5. Check if the brass M4 threads on the lid have been pulled out.
6. Torque the lid to 1 Nm to prevent damage to the M4 threads.
Water should not be able to get in, all components are IP67 or higher.
If water does seep in, the housing might be damaged or the housing cover was mounted incorrectly. The 3 vents let in air, but block moisture.
To connect the Ranos dB to your private LoRa network, download the DSS Connect App from Google Play for network settings (LoRa keys).
1. Your local provider will deliver the LoRa network keys.
2. Download the Ranos dB from Google Play for LoRa network settings (LoRa keys) and connect the sound sensor to your private LoRa network.
We have developed a technical blueprint in which we send audio fragments via LTE-M. You will find more information about this product under Ranos Tag.
The internal clock is not accurate enough to be set just once. After some time, it needs to be synchronized again using GPS time. Time sync works even when GPS is set to “off” or “once”.
We do not use the LoRa timestamp in the message received through the gateway, because this is not the timestamp of the measurement itself.
You need a USB-B male to whichever USB connector your (Android) mobile phone is using. Currently, the most commonly used one is the C male or Micro-B male.
A USB-B male to USB-C and Micro-B male cable is included.
No, not yet (Android only). We are working on it.
The GPIO pins are not made available to be programmed by the user. We can program these upon request.
No, we are using an Atmel microcontroller with a certified LoRa module.
There is an easy-to-use online tool for checking the performance of the solar panel of the Ranos dB in your region. Below, you will find the link to this tool. There you can read the necessary steps to make the calculations of solar power production in your own city or region.
Please follow the next steps:
- Select your geolocation on the map at the right.
- Select OFF-GRID in the middle.
- Fill out:
- Solar radiation database: PVGIS-CMSAF
- Installed peak PV power [Wp]: 9,2 Wp
- Battery capacity [Wh]: 72 Wh
- Discharge cutoff limit [%]: 40%
- Consumption per day [Wh]: 0,17 W
- Upload consumption dataSlope [°]: 35°
- Azimuth [°]: 0°
- Click on the button “Visualize results” to see the power production and battery performace of the solar panel in your region. Results appear underneath the webpage.
No. However, we haven’t experienced any problems yet, as the snow will easily slide off of the panel due to its angled position. Plus, the dark color of the solar panel helps to attract heat to melt the snow.
If the battery has run empty, you can place the Ranos dB outside to allow the solar panel to charge it. once is has charged enough, the battery will power the PCB again and automatically resumes operation.
Note: To protect the lead battery, the charge regulator on the PCB will switch off the power automatically if the voltage of the battery is below 4 volt.
The energy consumption is largely determined by payload size and the transmission frequency. If the battery voltage drops too far during operation, please change the settings by using a downlink or the Android app.
No, this is not possible. It is, however, possible to power (and run) the Ranos dB by USB. To do this, the power switch on the PCB must be set to “USB”.
Set the power switch on the PCB to “USB” and use a regular phone charger to power the Ranos dB. In this switch position (“USB”), the battery is switched off.
We use a lead acid battery (Yuasa NP12-6), because these batteries perform better in cold weather than lithium-ion. Our battery must be able to charge and discharge at very low and high temperatures, including below zero.
Most of our sound sensors are installed in countries with a lower average temperature, like Norway and Finland. In warmer countries like Italy, including the summer period, we haven’t experienced any problems with heat.
Yes, the ‘’sweet spot’’ for best performance is around 20 degrees Celsius, but the battery has been oversized to account for temperature variations. Battery capacity is reduced at colder temperatures, but there should be enough headroom (extra capacity) for normal operation at temperatures to around -10 °C.
At higher temperatures, aging rate is increased. Even at 50 degrees Celsius, however, battery service life should still be at least 1 year .
Sand particulates shouldn’t be a problem, sand will wash off of the panel by rain.
Please note that the battery charge state cannot be calculated very accurately based on the voltage alone. However, you can use it to estimate the state of charge or the battery health.
This is because the voltage vs. charge curve is not linear, and because the battery is being charged during the day. The latter will cause te voltage to read higher during charging. During the night, the voltage reading will be more accurate, as the battery will ‘’have rested’’.
We are using Yuasa NP12-6 batteries. At 100% charge, the open circuit voltage is 6V. At 0% charge, the open circuit voltage is 5,75V. You can consider the voltage measured during the night as an ‘’open circuit’’ due to the low power consumption.
You can use this information for the following formula:
100-((6-voltage bat measured)/((6-5,75)/100))
For indoor or testing any USB A male to USB B male cable can be used, make sure the cable length is below 2 meters.
For outdoor applications sealed USB cables/connectors are needed.
The USB connector used in our sensor is the Conxall DCP-USBBT-USBA, this connector facilitates sealed connections.
The corresponding sealed off the shelf cable is the Conxall DCM-USBBT-R5 (the supplied cable length is 5m, cut the length down to 2m or less). The sensor side of this cable consists of a sealed USB B connector, the supply side of this cable consists of stripped/tinned wires.
Alternatively the Conxall DCC-USBBT-150 can be used with a standard USB A male > USB B male cable and an USB powersupply.
In this case extra care needs to be taken for waterproofing the USB PSU and connections.
Note: Flip the power switch on the PCB to “USB”.
The powersupply should output 5VDC and should be able to supply at least 0,4A. The powersupply needs to be low noise (<200mVp-p ripple and noise).
The following powersuplies should be suitable for many applications:
- Recom RACM18-05SER/W – IP68, compact
- Meanwell GS05E-USB – Wallwart, USB A output connector
- Meanwell IRM-30-5ST – Enclosed/insulated industrial PSU
Note: Flip the power switch on the PCB to “USB”.