TRH420
Precision USB temperature and relative humidity sensor
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Volume discounts available for modular OEM integration projects. Contact sales@dracal.com for more information.
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| Temperature (°C): | -40 to 70 | ±0.1 |
| Relative humidity (%RH): | 0 to 100 | ±1.5 |
| Dew point: | Calculated in real-time |
- 2-layer filter
- Efficiency: >99.99% of particles as small as 200 nm
- RoHS3 and CE compliant
- 3 years warranty
PRODUCT OPTIONS
- 3-point user calibration mechanism (CAL option)
- COM communication (VCP option)
- Traceable to the CNRC (NIST) certificates
FREE DATA LOGGING AND MONITORING SOFTWARE
Learn more and download DracalView:
- Get up-and-running in less than 3 minutes
- Operates under Windows, Mac OS X and Linux
- Real-time on-screen graphing and logging
- Configurable log file format
- Log interval down to 0.5 second
- Configurable units (°C, °F, K…)
- Simultaneous use of unlimited Dracal sensors supported
- Simple user-calibration (products with the CAL option)
- Connectivity with SensGate Wi-Fi/Ethernet gateway
EASY TO INTEGRATE IN YOUR OWN APPLICATION
- One portal page to easily get started
- Easily switch between USB CLI and Wi-Fi/Ethernet CLI
- Code samples available for many programming languages
- Usable with LabView (Guide here)
All command-line tools (CLI) are packaged with DracalView
Description
TRH420: High-Precision USB Temperature and Relative Humidity Sensor.
The TRH420, a member of the TRH series, is a USB sensor designed for environmental temperature and relative humidity measurements, offering improved precision of ±0.1°C for temperature and ±1.5%RH for relative humidity. Its digitally calibrated, linearized, and factory-compensated sensor allows precise and interchangeable measurements, with a probe operating range of -40°C to 70°C. With a resolution of 0.015°C for temperature and 0.01%RH for relative humidity, it is ideally suited for applications requiring precise monitoring of these parameters. Its 1-meter USB cable and USB-powered operation provide excellent installation flexibility, while its robust design protects it against challenging environmental conditions.
Like all Dracal measurement instruments, the TRH420 is compatible with free software tools, making it an essential component of a DAQ solution. For those who wish to integrate the TRH420 into their system, there are two options available: command line tools and VCP mode. If you prefer a graphical interface, DracalView is the appropriate choice.
Easy to use in your applications
- Virtual COM option (VCP)
- dracal-usb-get: command-line data integration tool
- dracal-sensgate-get: command-line tool for wireless access to sensors connected to a SensGate
- RVCP: REST API for wireless access to VCP instruments connected to a SensGate
Multiple integration and code examples, including Python, C, C++, Java, Node.js, C#, Grafana and LabVIEW.
Free data monitoring and calibration software
Be instantly operational with DracalView: our free data visualization, logging and calibration software
- Works under Windows (Win7/8/10/11 64&32-bit), Mac OS X and Linux
- Simultaneous visualization and logging of an unlimited number of sensors
- Automatic synchronization with our Wi-Fi gateway
- Easy calibration mechanism open to the end-user
Application examples
- Use as a working reference
- Integration into a quality control system in production (Lumotive)
What is included
- One (1) TRH420 measuring instrument
- One (1) USB Cable
- Quick installation guide
- Data acquisition solution for DAQ system
Available options
Specifications
Temperature (probe)
- Probe operating range: -40°C to 70°C
- Accuracy (typical):
- ±0.1°C (20°C to 60°C)
- ±0.2°C (-40°C to 70°C)
- Resolution (typical): 0.015°C
- Repeatability (typical): 0.06°C
Relative humidity (probe)
- Operating range: 0 to 100 %RH
- Accuracy at 25°C (typical)
- ±2.0 %RH (0 to 80 %RH)
- ±3.0 %RH (90 to 100 %RH)
- Accuracy at 0 to 70°C (typical)
- ±1.5 %RH from 0 to 70 %RH
- Resolution (typical): 0.01 %RH
- Repeatability: 0.1 %RH
Probe filters
- First filter material: Polyethylene terephthalate (PET) mesh
- Second filter material: PTFE membrane
- Efficiency: >99.99% for particles of 200 nm
Miscellaneous
- USB cable length: 1 meter (3 ft.)
- Operating temperature range (USB cable interface): 0°C to 70°C
- Powered through USB
- This product can operate at 100 %RH but is not waterproof. Protect the sensor and CPU against direct exposure to water or snow. Extra housing may be required depending on the application.
- It is recommended that the probe be installed pointing down to reduce the risk of water infiltration or build-up in the probe.
- RoHS3 and CE compliant.
Available channels
(As displayed in our logging software DracalView)
| Channel Id* | Description | Type | Nature |
|---|---|---|---|
| 00 | SHT31 Temperature | Temperature | Real |
| 01 | SHT31 Relative Humidity | Relative Humidity | Real |
| 02 | Dew point | Dew point | Virtual |
| 03 | Humidex | Humidex | Virtual |
| 04 | Heat index | Heat index | Virtual |
Dimensions
Units: Inch [mm]
Virtual COM port communication protocol (option)
This product is available with the option of communication via virtual COM port protocol. Products with this option can be freely converted between USB and VCP communication modes. For more information about this option, consult the documentation of the VCP option.
Of note, for Windows 7 users, here is the installation procedure.
Here is what the invocation of the command INFO returns for this product:
I,Product ID,Serial Number,Message,SHT31 Temperature,C,SHT31 Relative Humidity,%,*860Aas well as an example of what this product transmits:
D,VCP-TRH420,E16147,,34.5731,C,37.2915,%,*BEE1
D,VCP-TRH420,E16147,,34.5731,C,37.3373,%,*6A9E
D,VCP-TRH420,E16147,,34.5598,C,37.2625,%,*2FCF
D,VCP-TRH420,E16147,,34.6025,C,37.3098,%,*7F29
D,VCP-TRH420,E16147,,34.5891,C,37.3404,%,*87A0
3-point user calibration mechanism (option)
This product can be equiped with a 3-point user calibration mechanism. Devices equiped with this feature are eligible for calibration and certification in an accredited ISO/IEC 17025 laboratory. You will find here more information about NIST traceable certificates.
Free data logging software
- Real-time on-screen graphing and logging
- Supported by our DracalView data logger software and tools
- Operates under Windows (Win7/8/10/11 64&32-bit), Mac OS X and Linux
- Configurable log file format with log interval down to 0.5 second
- Configurable units (°C, °F, K...)
- Simultaneous use of unlimited Dracal sensors supported
- Seamless connectivity with SensGate Wi-Fi/Ethernet gateway
- Command-line tool dracal-usb-get is also available (packaged with DracalView)
- Use it in your own application easily! We provide code samples for many programming languages
- Usable with LabView (Guide here)
- And much more! Visit our DracalView software WEB page for more information
Do you have STEP/CAD files of your instruments?
You can find them on each instrument page under the Datasheets tab if available.
Are your sensors battery-powered?
No, they are not. They are powered via the USB plug; therefore, they must be plugged in to transmit data.
Can the device measure at a frequency of 1 Hz (1 data per second)?
Yes, all our TRH sensors can easily generate data at a frequency of one per second. However, the response time (t63%) of the TRH200 is smaller: 5 seconds compared to 8 seconds for the other TRH sensors.
Why is the temperature reading more sensitive in the TRH compared to the sensor on a demonstration board?
Our sensor is installed on a tiny PCB (printed circuit board), which makes it more responsive because:
- There is less thermal mass.
- Air circulates more rapidly around the sensor.
The longer neck on the PCB reduces thermal corruption from the PCB.
What is the advantage of a PTH sensor over a TRH sensor?
The PTH sensor includes a barometer, while the TRH sensor does not. However, in terms of temperature and relative humidity measurement accuracy, there are equivalents in both series. The usefulness of knowing atmospheric pressure depends on your application. For measuring air parameters at different altitudes, it can be advantageous to know the atmospheric pressure. It impacts condensation, a critical phenomenon for precision electronics.
My relative humidity reading is above 100% RH. What is happening?
The first question to ask is whether you have performed relative humidity calibration. If so, here is a simple procedure to test before contacting us:
- In DracalView, in the Sources tab, type [“channel identifier”_nc] as the formula for a mathematical channel.
- In the GraphView tab, check if the reading of this formula is corrected.
- In the Sources tab, click the Calibrate button and then check the Disable calibration box.
- In the GraphView tab, check if the reading of the relative humidity channel is corrected.
- If so, we recommend removing the calibration points by clicking the red X next to each one.
Can I use the instrument within the probe’s operating range, even though the cable and housing temperature range is 0°C to 70°C?
The cable and housing were not designed for temperatures below 0°C. However, all components are compatible with temperatures ranging from -40°C to 85°C. We recommend securely fastening the measuring instrument and not bending the wire if you wish to take measurements below 0°C.
Regarding the aluminum probe with a silicone-covered wire, it is advisable to place only the probe in an environment above 70°C.
Can the probes be submerged in water?
No. These are instruments for measuring air parameters. Although the probes can tolerate 100% RH (Relative Humidity), they may stop functioning if water comes into direct contact with the sensor. In such cases, you should dry it, preferably by heating the instrument to 60°C with a stream of air. Once dry, it should work again.
All our temperature and relative humidity sensors have an IP rating (Ingress Protection rating) of 54, which means they are protected against dust and water splashes for a short time.
Is the individual calibration of the measuring instruments done at the Dracal factory
At the Dracal production factory, a pass/fail type of testing is conducted during the production of the measuring instrument. Additionally, the component manufacturer carries out individual calibration at their factory before being shipped to us. These calibrations are not ISO17025 certified, but if your industry does not require this standard, you can confidently use Dracal’s USB adapters upon receiving them.
How do I request a quote?
We have created the easiest possible quote request system for you.
1. Create an account and log in.
2. Then do whatever you would do while shopping, then click on the shopping cart in the top right.
3. In your cart, click on “Switch to quote”, then at the bottom of the page “Proceed to quote”. You will not be asked for any payment information.
You will then receive a quote by email, which you can accept and pay within 30 days.
What are the advantages of choosing a calibratable instrument (-CAL option)?
The devices with the 3-point calibration mechanism have a longer lifetime as it is possible to compensate for the natural drift of the measurements. The cost/lifetime ratio is thus considerably reduced and, just as importantly, this choice is environmental friendly.
These devices can be easily calibrated and certified by external resources (including our ISO17025 certified partner laboratory) and allow you to synchronize your various devices between them.
What are the advantages of using your USB communicating devices over other technologies?
| 1. Connection security. | 6. Continuous power supply. |
| 2. Instant access to data. | 7. Low-power supply. |
| 3. Data confidentiality. | 8. Self-sufficiency. |
| 4. Data reliability. | 9. Technology persistence over time. |
| 5. Fast response time. | 10. Universal access. |
Can I use your measurement devices while maintaining my current software infrastructure?
Yes, you own your data. To integrate your data, you can either use our CLI (command line interface) for which we have plenty of code examples or for more advanced users, by choosing the VCP (Virtual COM Port) option when selecting your product.
How many devices can be simultaneously managed by your software tools?
Unlimited number of similar and different devices, provided your system supports the load.
What is your warranty policy?
Dracal Technologies guarantees the incomparable speed of use and the exceptional quality of its products, that they are made of new materials, assembled and tested in our factory in Canada, in processes that respect human rights and the environment. We guarantee the absolute absence of any form of programmed obsolescence, and that conversely, we deploy sustained efforts on both our electrical and mechanical designs to extend the life of our devices as long as possible so that the results of the efforts invested by our customers last over time but also, and just as importantly, to preserve our planet. We guarantee unlimited access to all updates of our free software tools. We offer a 2-year material warranty.
