Temperature and humidity monitoring
The SimtoLink temperature and humidity sensor uses a high-accuracy digital temperature and humidity chip at the sensing front end, such as the SHT30 or AHT20. The chip completes analog-to-digital conversion and the calibration-coefficient calculation internally, and presents a reading on a digital bus. It is a digital sensor, unlike a thermistor or thermocouple probe that needs an external ADC. After conditioning, readings are reported by digital communications such as RS485/Modbus RTU or LoRa. Where a project needs analog transmission at 0–10V or 4–20mA, choose a custom model or add an external acquisition module.
Range and units (typical; the datasheet governs): temperature measurement range -40℃ to +85℃ (degrees Celsius, ℃); relative humidity measurement range 0%RH to 100%RH (%RH is the ratio of the present vapor pressure to the saturation vapor pressure at the same temperature). The accuracy figures above (±0.3℃, ±2%RH) are typical values in a stable environment, with the specified supply and calibration. Near saturation, or when moisture condenses on the surface, the humidity reading can shift for a time. Keep the probe in a non-condensing condition and calibrate it on a regular schedule.
It fits server-room monitoring, warehouse logistics, and smart agriculture, with RS485/Modbus or LoRa wireless output for a networked install. The industrial enclosure stands up to electromagnetic interference and holds a stable output in hot, humid air. SimtoLink has worked in environmental monitoring for years and has supplied temperature and humidity monitoring to hundreds of customers, including data centers, pharmaceutical workshops, museums, and archives.
Parameters and interfaces
SimtoLink offers several builds by communications method and ingress rating, so the same sensing job can be fitted to different rooms. The table lists typical figures:
| Configuration | Typical specification | Notes |
|---|---|---|
| Wired | RS485/Modbus RTU | DC 12–24V, function codes 03/04 |
| Wireless | LoRaWAN Class A | Air-interface battery life >2 years |
| Measurement range | Temperature -40℃ to +85℃; humidity 0%RH to 100%RH | Step response to 63% typically <30s (still air; see the datasheet) |
| Operating conditions | Operating -40℃ to +85℃; storage -40℃ to +90℃ | Separate from measurement range: the range is the quantity the probe can measure; this row is the temperature band in which the circuit runs reliably |
| Chip and drift | SHT30, AHT20 | Long-term drift <0.1℃/year |
Power consumption <0.5W. Operating temperature and storage temperature of the complete unit are already in the table above. Do not confuse them with the temperature measurement range. The figures are typical for the standard model. The product datasheet governs.
Typical applications and results
From data centers to cold-chain logistics and museums, the sensor covers environmental monitoring and HVAC interlock across industries. Typical jobs and what they delivered:
Data center server-room monitoring
One data center server room installed 120 temperature and humidity sensors. A Modbus gateway brings them onto the monitoring platform for 7×24 temperature and humidity monitoring and air-conditioning interlock, and room PUE moved from 1.6 to 1.35.
Cold-chain temperature alarms
A cold-chain operator installed sensors in 15 cold stores. Edge gateways raise a temperature alarm within seconds, so perishable quality stays intact.
Museum collection climate
A museum placed wireless sensors in 8 galleries, with no new cable runs. A LoRa gateway sends the readings to the environmental monitoring system, so the climate around the collection is watched and logged continuously.
GMP monitoring in a pharmaceutical cleanroom
A pharmaceutical plant installed the sensors in cleanrooms to meet GMP environmental monitoring. Temperature and humidity are captured as they change and kept as a traceable record.
Selection and installation
- Communications: Indoor rooms can use the wired RS485 model, which costs less and stays stable. Scattered points are better on the wireless LoRa model, which avoids new cable. One LoRa gateway can take 500+ nodes.
- Ingress and mounting: High humidity, such as a cold store, needs IP65 or higher. Keep the sensor out of direct sun and away from air-conditioner outlets, so the reading is the room and not a local draft.
- Wiring and network: RS485 should run as a daisy chain, with a 120Ω termination resistor at the end of the bus and a single bus no longer than 1200 meters. LoRa sensors need to sit inside the gateway’s coverage.
- Calibration and maintenance: Set a patrol and, each quarter, check that the sensor is working and the data is still accurate. SimtoLink includes one year of free calibration; after that, units can be sent in or calibrated on site. Remote service watches online rate and data quality as they happen.
- Delivery support: If the room needs a local reading, choose a model with an LCD. Large jobs can add a redundant gateway and a spare link. Once the application, the environment, and the interface are clear, SimtoLink can recommend a model.
Rollout and maintenance
Install the temperature and humidity sensors in this order:
SimtoLink handles selection, installation, and calibration, and can customize range, communications protocol, and outline size.
Service and support
The same team can survey a large site and write the design. Warranty is one year, maintenance covers the life of the unit, and technical support runs 7×24. Product manuals and a quoted proposal are available on request.