
Flameproof Earthing Resistance Monitor (Ex d)
Flameproof (Ex d) earthing resistance monitoring device for hazardous areas such as petrochemical plant and fuel stations.
Flameproof Earthing Resistance Monitor (Ex d)
Performance Overview:
The HD-HLDZ-LoRa/Ex and HD-HLDZ-NB/Ex flameproof earthing resistance monitors are specially designed for explosive atmospheres. They are mainly used for online monitoring of the connection status of earthing down conductors, earthing resistance and metal bonding resistance. The monitor adopts non-contact measurement technology and requires no self-test process, supporting real-time online monitoring. It avoids the cumbersome traditional contact measurement that requires disconnecting wiring and on-site construction, meeting the safe and efficient monitoring requirements of explosive environments.
HD-HLDZ-LoRa/Ex: LoRa communication version, requires a LoRa gateway. The LoRa gateway manages all earthing resistance monitor nodes in a designated area, controls the measurement actions of each node device and reads the measured data. Under clear line-of-sight conditions, the LoRa communication distance can reach 3 km.
HD-HLDZ-NB/Ex: NB-IoT communication version, supports scheduled periodic measurement. Measured data can be uploaded to the cloud server via the NB-IoT network. Users can log in to the platform with the back-end management system account provided by the manufacturer to view the operating status and historical collection data of the monitor. No external gateway deployment is required, making it suitable for single-point or distributed explosion-proof monitoring locations. Note: When choosing the NB-IoT communication version, if the device is used outside Guangdong Province, contact the manufacturer to modify the registration address information of the IoT card, otherwise communication may be abnormal.
Technical Parameters:
| Model | HD-HLDZ-LoRa/Ex | HD-HLDZ-NB/Ex |
|---|---|---|
| Explosion-proof mark | Ex db mb IIB T6 Gb | |
| Power supply | 7.2Vdc (battery powered, supports standby of at least 3 years) | |
| Resistance range | 0.01Ω~100Ω | |
| Resistance measurement accuracy | ±2%rdg±3dgt (20℃±5℃, below 70%RH) | |
| Resolution | 0.001Ω | |
| Lightning interference immunity | ≤100kA (8/20us) | |
| Communication | LoRa, NB-IoT (select one) | |
| Display | LCD screen | |
| Low-battery alarm | Yes | |
| Overflow indication | LCD shows "OLΩ"; resistance reads 500Ω on command | |
| Range switching | Fully automatic | |
| Protection rating | IP66 | |
| Operating temperature & humidity | -20℃~55℃; 20%RH~90%RH | |
| Dimensions L*W*H | 205mm*223mm*168mm | |
| Earth wire through-hole aperture | 51mm×27mm | |
| Mounting | Earth wire passes through the sensor center hole | |
Applications: Suitable for places with explosive risks such as gas stations, tank farms, oil pipelines and well sites.
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