ES-Net

ES-Net is the base model in the ES series. It has no screen and no buzzer. Measurement, time sync, and communication match ES-Pro. For setup, see Installation and Wi-Fi setup.

Hardware versions

Version	Description
1.0	The first hardware version.
3.0	A new board. It uses the same circuit board as ES-Pro 3.0.

Every hardware version uses the same ES-Net firmware. The seismometer detects the version when it boots.

Note

The dimensions, weight, and power consumption below were compiled from data from before version 3.0 was released. Values for version 3.0 have not been published separately.

Appearance

Item	Value
Dimensions (L × W × H)	70 × 35 × 24 mm
Weight	36.8 g
Protection rating	IP10 (not waterproof; indoor use only)
Operating temperature	-20 – 65 °C (60 °C or below is recommended)

High temperature

The electronics were tested to operate at 65 °C, but the case is PLA. It may deform if it stays above 60 °C for a long time. Do not place it in direct sunlight or near a heat source.

Electrical

Item	Value
Power connector	USB Type-C
Input voltage	4.5 – 5.2 V

Power consumption

Mode	4.5 V	5.2 V
Connected (Wi-Fi)	0.4 W	0.6 W
Standalone (Wi-Fi off)	0.7 W	0.8 W

Sensor

Item	Value
Type	Three-axis MEMS accelerometer (strong-motion seismometer)
Sample rate	50 SPS
Resolution	16 bit
Measurement range	±2 g (about 1961 gal)
Frequency range	DC – 25 Hz
Noise density	60 µg/√Hz

Intensity calculation and filtering

The seismometer calculates Japan Meteorological Agency (JMA) instrumental seismic intensity on the device. After it boots, it must collect 60 seconds of data before it starts outputting intensity.

Filter	Details
Time-domain high-pass (HPF)	11th-order IIR, cutoff frequency about 1 Hz
Time-domain low-pass (LPF)	11th-order IIR, cutoff frequency about 10 Hz
Frequency domain (for instrumental seismic intensity)	Attenuation below 0.5 Hz and above 10 Hz, with period-effect compensation √(1/f)

Time synchronization

Item	Value
Method	NTP. It runs automatically after the device joins Wi-Fi
Sync interval	2 – 10 minutes, adjusted automatically from clock drift
Time error	Usually ±10 ms
Time accuracy	50 ppm

Networked mode and not-networked mode both sync the clock. Standalone mode does not join Wi-Fi, so it does not sync the clock, and timestamps may be inaccurate.

Communication

USB

Item	Value
Interface	USB Type-C serial port (UART)
Transfer rate	115200 bps
Data format	Binary

Output:

• Three-axis acceleration (gal), 50 samples per second.
• Acceleration value a (gal) used for instrumental seismic intensity, about one sample every 0.5 seconds. It can be converted to instrumental seismic intensity.

Note

Starting with firmware 26w41a, USB uses a new binary format. Each record includes a sequence number and a CRC checksum. To read the data on a computer, use a version of QuakeWatch-Pro that supports the new format. See QuakeWatch-Pro.

Wi-Fi

Item	Value
Band	2.4 GHz
Standard	802.11 b/g/n
Antenna output power	20 dBm maximum

Bluetooth

Bluetooth turns on only while you set up Wi-Fi (pairing mode) or update firmware (BLE OTA mode), so ExpTech Home can connect. During normal operation, Bluetooth is off.