Product category
IoT Temperature & Humidity Sensors and Probes (PT100, RS485 MODBUS, 1-Wire)
An IoT temperature sensor is the measuring element that feeds a data logger or gateway, which then sends readings to the cloud for alerts and reports. The choice of sensor, whether a PT100 RTD, a thermocouple, a 1-Wire digital probe or an RS485 MODBUS transmitter, decides the range, accuracy and cable run you can achieve. This page is for instrumentation, facilities and QA engineers specifying monitoring points. Ideabytes IoT supplies RS485 MODBUS temperature, humidity and CO2 sensors, a 1-Wire digital probe and a USB probe, and its multi-channel loggers accept PT100 and PT1000 probes.
4 models in this range
- GeM registered
- 21 CFR Part 11 reports
- Made in India
IoT sensors & probes: 4 models
Every model logs to the Ideabytes cloud dashboard and produces audit-ready 21 CFR Part 11 reports.
Showing 4 products
MODBUS RS485 Temperature and Humidity Sensor
The IBI-TH485 temperature and humidity sensor is designed based on the RS-485 communicationinterface, compatible with the standard Modbus-RTU protocol, and can be connected to the Modbus network to achieve temperature and humidity measurement and monitoring.
- •Low power consumption
- •Fully calibrated
- •High precision and good consistency
Digital Temperature Sensor (1-Wire)
Measurement Range: –50°C to +120°C IBI-T1W is a digital temperature sensor and provides accurate temperature measurements with minimal wiring and is suitable for industrial, IoT, and aviation-grade applications.
- •1-Wire communication digital temperature sensor
- •Wide temperature measurement range
- •Factory calibrated
CO2 Sensor (RS-485 MODBUS)
The IBI-A-C485 uses Non-Dispersive Infrared (NDIR) dual-beam technology to measure CO2 by detecting infrared absorption at a CO2-specific wavelength.
- •Optical measurement is inherently oxygen-independent and shows low cross-sensitivity to typical indoor gases.
- •Devices are factory calibrated for ppm-level accuracy with minimal re-calibration under normal indoor conditions.
IBI-UTPROBE50 | USB Temperature Probe
Measuring Range -40°C to +50°C
- •Data can be viewed/recored using Android Mobile App
- •Android SDK will be provided to integrate with your existing android application
- •Probe sends data every second
Compare models
| Model | Interface | Accuracy | Sensor Type | Range | Temperature Range |
|---|---|---|---|---|---|
| IBI-A-TH485 | — | ±0.3℃(0~60℃); ±0.5°C for other range | — | -30～70℃ | — |
| IBI-T1W | 1-Wire | ±0.5°C (–10°C to +85°C) | — | –50°C to +120°C | — |
| IBI-A-C485 | RS-485 | ±(50 ppm + 3% of reading) | NDIR Dual-Beam | 0–10,000 ppm | — |
| IBI-UTPROBE50 | — | — | Thermocouple K-type | -40°C to +50°C | -40°C to +50°C |
What is a PT100 temperature sensor?
A PT100 is a resistance temperature detector (RTD) made from platinum whose resistance is 100 ohms at 0°C and rises in a predictable, almost linear way as temperature increases. The logger passes a small current through the element, measures the resistance and converts it to temperature. Because platinum is stable and repeatable, the PT100 is the default RTD temperature sensor in pharma, food processing, laboratories and industrial plants where readings must hold up to calibration and audit.
PT100 probes are wired in 2-wire, 3-wire or 4-wire form. Extra wires let the instrument cancel the resistance of the lead cable, so 3-wire suits most field runs and 4-wire is used where the highest accuracy is needed.
PT100 vs PT1000 vs thermocouple vs 1-Wire digital sensors
Each sensor type has a sweet spot. Pick by range, accuracy and how far the sensor sits from the logger.
- PT100 (RTD): 100 ohms at 0°C, wide range and good long-term stability. The standard choice for freezers, ultra-low temperature storage, process lines and validation work.
- PT1000 (RTD): the same platinum principle at 1,000 ohms, so lead-wire resistance matters less on long cables and low-power electronics.
- Thermocouple (for example K-type): two dissimilar metals produce a small voltage. Robust, fast and inexpensive, with a very wide range, but usually less accurate than an RTD near room temperature.
- 1-Wire digital sensor: the probe digitises the reading itself and sends it over a single data line, so wiring is simple and the reading is not affected by cable resistance. Best for cold rooms, refrigerators and general IoT monitoring.
PT100 probes for our multi-channel data loggers
The Ideabytes 4-channel and 8-channel loggers (IBI-WTR4, WTR8, MTR4, MTR8, OTR4 and OTR8) accept PT100 2/3/4-wire inputs, with PT1000 2/3/4-wire as an option, over a range of -200°C to 550°C and 0.5°C (0.05% of full scale) accuracy. The single-channel 350 models (IBI-WT350, MT350, ET350 and OT350) take an RTD PT100 probe for -200°C to +350°C. Probe style and cable length are specified with the order.
If you need several PT100 points on one chamber, autoclave, oven or freezer bank, start with the multi-channel temperature data logger category rather than buying individual sensors.
RS485 temperature and humidity sensor and CO2 sensor (MODBUS RTU)
The IBI-A-TH485 is an RS485 temperature and humidity sensor on the standard MODBUS RTU protocol. It uses an SHT30 element, measures -30°C to 70°C (±0.3°C from 0°C to 60°C) and 5 to 95% RH (±2% from 10% to 90% RH), runs from DC 5 to 24 V and sets its address with DIP switches, so a replacement can be fitted without reprogramming.
The IBI-A-C485 is a CO2 sensor on RS485 using NDIR dual-beam measurement, 0 to 10,000 ppm with ±(50 ppm + 3% of reading) accuracy and 1 ppm resolution. The dual-beam design compensates for light-source ageing and dust, and the MODBUS registers map easily into BMS, HVAC, PLC and SCADA systems.
Temperature sensor for IoT: choosing a probe for a data logger
Start with the range. Refrigerators, cold rooms and ambient warehouses sit comfortably within the -50°C to +120°C of a 1-Wire digital probe. Deep freezers at -80°C, liquid nitrogen storage, ovens and autoclaves need a PT100 probe on a logger rated for -200°C and above. Then consider accuracy near the point that matters: a pharma fridge held between 2°C and 8°C needs a sensor whose accuracy is specified around that band, not just across its full range.
Next look at the cable run and the environment. Long runs favour RS485 (a digital bus designed for distance) or a 3 or 4-wire RTD. Wet, washed-down or outdoor locations need a sealed probe, such as the IP67 stainless-steel IBI-T1W. Finally, decide whether the sensor must be replaceable without recalibrating the whole system; digital sensors with their own calibration make swaps quicker during audits.
Connecting RS485 MODBUS sensors to the gateway
RS485 sensors are designed to be daisy-chained on one two-wire bus, each with its own address. To bring them onto the cloud, connect the bus to an Ideabytes MODBUS gateway: the IBI-CSC50R over Wi-Fi or the IBI-CSC50RM over 4G with a built-in M2M SIM. Each gateway can communicate with up to 15 MODBUS RTU devices and monitor up to 30 parameters, with 8 parameters configured by default and additional configuration charged separately.
Once connected, sensor readings appear in the same dashboard, alerts and 21 CFR Part 11 compliant reports as the Ideabytes data loggers. That lets one platform cover a mixed site: loggers on the fridges and freezers, RS485 temperature and humidity sensors along warehouse racks, and CO2 sensors in incubator rooms or occupied spaces. The IBI-A-TH485 supports 4800, 9600 or 19200 bps, so it can also sit on an existing BMS or PLC network if you already run one.
Digital temperature sensor (1-Wire) and USB temperature probe
The IBI-T1W is a 1-Wire digital temperature sensor in a waterproof 6 mm stainless-steel probe rated IP67, with a PTFE cable (3 metres standard, customisable) and a GX12 aviation connector. It measures -50°C to +120°C with ±0.5°C accuracy from -10°C to +85°C and is supported on the IBI-WT120 and IBI-MT120 loggers.
The IBI-UTPROBE50 is a handheld K-type thermocouple probe that plugs into an Android phone over USB OTG (micro USB and Type-C), reads -40°C to +50°C and sends a reading every second. An Android SDK is available to build it into your own app.
Used for
Frequently asked questions
What is the difference between a PT100 and a PT1000 sensor?
Both are platinum RTDs. A PT100 has a resistance of 100 ohms at 0°C and a PT1000 has 1,000 ohms. The higher resistance of a PT1000 makes lead-wire resistance less significant on long cables. Ideabytes multi-channel loggers accept PT100 in 2, 3 or 4-wire form, with PT1000 as an option.
Which temperature sensor is best for IoT monitoring?
For cold rooms, fridges and general facility monitoring, a 1-Wire digital probe or an RS485 MODBUS sensor is simple to wire and reads directly in degrees. For very low or very high temperatures, process equipment and validation, use a PT100 probe on a multi-channel logger. Humidity and CO2 need their own sensors, such as the IBI-A-TH485 and IBI-A-C485.
Can I connect my own RS485 MODBUS sensors?
Yes, if they speak MODBUS RTU over RS485. The IBI-CSC50R (Wi-Fi) and IBI-CSC50RM (4G) gateways can communicate with up to 15 MODBUS RTU devices and monitor up to 30 parameters. Eight parameters are configured by default and further configuration is charged separately, so share the register map when you enquire.
Is there a Wi-Fi temperature and humidity sensor?
The RS485 sensors on this page are wired devices. For a temperature humidity sensor on Wi-Fi, either connect an IBI-A-TH485 to the Wi-Fi IBI-CSC50R gateway, or choose a Wi-Fi temperature and humidity data logger, which combines the sensor, display, memory and Wi-Fi in one unit.
How much does an IoT temperature sensor cost?
It depends on the sensor type, cable length, connector, quantity and whether a gateway and cloud software plan are needed to bring the readings online. Send the number of measuring points, the temperature range and the installation layout through the contact form and the team will propose a complete sensor and gateway set-up with a quote.
Do the sensors come with a calibration certificate in India?
The RS485 temperature and humidity sensor, the CO2 sensor and the 1-Wire probe are factory calibrated. NABL-traceable calibration certificates are available on request, which is what most Indian pharma, hospital and food auditors ask to see. Ideabytes products can also be purchased through GeM by government buyers.
Related reading
Product categories
From the blog
Need help choosing the right logger?
Tell us what you store, how many points you need to monitor and which audits you face. Our team in Hyderabad will recommend a setup and send a quotation.