Temperature – Pressure – Humidity (Modbus)


TPH‑1™ is a digital sensor that measures air temperature, relative humidity, and barometric pressure. TPH‑1 uses the Modbus RTU protocol to connect to computers, programmable logic controllers (PLCs), some data loggers, and, of course, Dyacon Weather Stations.




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TPH‑1™ is a high-quality, combination temperature, barometric pressure sensor, and humidity module. All sensing elements are integrated into a single probe and radiation shield. TPH‑1 is a low‑power, digital‑output module with a Modbus RTU interface. (More about Modbus.)

TPH‑1 is compatible with Dyacon control modules and Modbus host devices, such as programmable logic controllers (PLCs) and personal computers.*

Configuration parameters, such as baud rate, sensor address, and calibration settings, can be programmed through documented Modbus commands. No special programming software is required.

Feature Summary

  • Air temperature
  • Relative humidity
  • Barometric pressure
  • Modbus output
  • Low-power operation
  • Wide input voltage

TPH‑1 is a standard component of Dyacon MS‑100 series weather stations.

*Personal computers will require an RS‑485 adapter and appropriate software.

Key Features


TPH‑1™ active sensing probe is housed in a compact radiation shield.

Radiation shield material is UV-stabilized PVC, which provides a rugged, low-mass construction that is designed to hold up over many years of use.


Temperature and relative humidity data are provided by a precision Swiss sensing element. The best-in-class capacitive sensor is highly accurate to the boundaries of its operational limits. The robust sensor is highly stable in harsh environments and exhibits minimal aging.

Barometric Pressure

A 24-bit ADC digital pressure sensor element has the capability to deliver +/- 1.5 mbar. (As a reference point, that equates to 10 cm of altitude change.)

Data Connection

Power and data are supplied through a 4-wire Modbus RS‑485 connection to a host device. Drawing a 1.4 mA average, TPH‑1 is suitable for solar-powered instrumentation systems. Additional sleep options can reduce average current to 60 micro-amps.


The TPH‑1 mounting system is compatible with standard 1” pipe, PVC, aluminum, or steel.

The horizontal mounting pipe positions the air sensor away from the mass of surrounding structures and equipment that may affect air flow and temperature. The pipe also serves as an air duct for the normal passive aspiration or the aspirator kit.


TPH‑1 can be used with the Smart-Fan™ aspiration kit for improved performance even in solar power stations. The mounting pipe serves as a remote exhaust, eliminating exhaust recirculation affecting sensor measurements.


Range-40°C to 80°Celcius
Accuracy+/- 0.2 K*
Reproducibility+/- 0.1 K
Response Time10 s
Long Term Drift<0.05 K/yr
Sensor TypePTAT

Range0% to 100% rH
Accuracy+/- 1.8% (10 to 80)
Reproducibility+/- 0.2% rH**
Hysteresis< +/- 1% rH
Linearity< +/- 1% rH
Response Time12 s
Long Term Drift<0.5% rH/yr
Sensor TypeCapacitive

Range10 mbar to 1300 mbar
Resolution0.01 mbar*
Accuracy+/- 1.5 mbar
Response Time0.5 ms (or request interval)
Long Term Stability<1 mbar/yr
Sensor TypeMEMS

*Full response range information is available upon request.

**The actual sensing element is highly sensitive (resolution of 0.02%), but message frame reports value in 0.1 increments.

Power Input5 VDC to 24 VDC (12 VDC nominal)
Current1.4 mAavg at 12 VDC full run mode†; 60 uAavg in sleep mode‡
Cable4 conductor, 24 AWG, stranded, foil shield w/ drain wire, outdoor-rated PVC jacket

MaterialUV-stabilized polycarbonate, white
Overall (WxDxH)13.2 cm x 13.4 cm x 13 cm
(5.2 in x 5.3 in x 5.1 in)
Weight w/ Cable288 g (10.2 oz)
Weight, Shield Only228 g (8.1 oz)

ProtocolsModbus RTU, RS-485, slave
OEM OptionsPacket structure, packet content (contact Dyacon for custom frame structure)

AspirationSmart-Fan aspiration kit
Structural FittingsElbow, coupler, crossover
Structural Pipe1 in x 2 ft

† Continuous full run mode, reading 200 range registers once per second.

‡ Timeout set to 50 or greater. No Modbus activity. See product manual for more information on this function.

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