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H1QT Temperature Sensor Datasheet


H1QT is a industrial-grade, fully calibrated digital temperature transducer; primarily designed to measure temperature in distribution pipes of gases and/or liquids. The solution offers a wide range of electrical connectivity options including RS485 and USB. The unit communicates using multiple protocol options. The unit offers multiple choices of physical connectors and can be used in a variety of environments.


Temperature sensor H1QT is designed for precision measurement of temperatures of gases and/or liquids inside distribution piping or open air. The main measurement body is made from stainless steel, so any measured medium which does not react with stainless steel (DIN 1.4301) can be measured.

The sensor uses very sensitive probe to measure temperature in the tip of the probe. The sensor is fully calibrated and linearized.

Sensors are designed, assembled and tested in EU under full EU legislation.

Mechanical information

The transducer is enclosed in a robust stainless steel enclosure. Rest of the body is made from UV-stabilized ABS-based plastics.

Technical parameters

Type of measurement temperature
Maximum measurement range -40 to 120C
Max pressure of measured medium 2 MPa
Measurement precision 0.1% of measured range
this combined precision accounts for non-linearity of measurement, hysteresis and repeatability
Long-term drift less than 0,03 deg. Celsius per year
Recommended calibration frequency once every three years
Operating temperature -40 to 85C
Power supply 5V - 30V DC
Communication protocol MODBUS RTU or SDI-12 or HTTP/JSON or MODBUS TCP/IP
Mounting options see order table below
Thread material DIN 1.4301 (AISI 304 / X5CrNi18 10) stainless steel
Plastic enclosure material ABS - ASA
Isolation resistance at 500V RIZ > 2 M Ohm
IP protection grade according to (IEC 60 529) EN 60 529 IP 66, also available as IP68 for full long-term liquid immersion

Temperature measurement


Ethernet version of temperature sensor H1QT-ETH supports up to 1Hz measurement cadency. All other versions support up to 20Hz measurement cadency.


Dimensions in [mm]

H1QT dimensions with A0 type connector (see below)


Testing applications and SDK and integration tools are promptly available on request via

Label description

Information included on the label:

  • Manufacturer
  • Full order code
  • Measurement range and precision
  • Serial number
  • IP rating


Order shall contain the following information:

  • Date and reference order number
  • Name and address of customer (including VAT number where appropriate)
  • Order code assembled from order tables including number of units and requested delivery date
  • Type of shipping
  • Optional extras to include (for example calibration certificates)

Order codes table

Measurement range (M)
M0-30C to +110C
MXspecial - on request
Measurement precision (% of measurement range) (P)
PXspecial - on request
Communication transceiver (R)
R1RS-485 (TIA-485(-A) / EIA-485)
R2USB 1.x (Win, Linux, MacOS drivers)
R3Ethernet (10Base-T) + PoE (802.3af)
RXspecial - on request
Connector type (A)
A0Weipu SP2112/P7 (IP68)
A1Valve connector DIN 43650-A (IP65)
A2USB Type-B (IP50)
A3Hirschmann CA3GS (IP67)
A4RJ45 (IP50)
A6Hirschmann CA6GS (IP67)
AXspecial - on request
Communication protocol (C)
CXspecial - on request
Mounting thread (T)
T3NPT 1/2
TXspecial - on request
Probe length including mounthing thread (L)
LXspecial - on request
Probe diameter (D)
DXspecial - on request
Order code example: H1QT-M0-P0-R1-A0-C0-T2-L2-DX=10mm
Measurement range (M0): -30C to 110C
Measurement precision (% of measurement range) (P0): 0.4%
Communication port (R1): RS-485
Physical connector (A0): Weipu SP2112/P7 (IP68)
Communication protocol (C0): MODBUS RTU
Mounting thread (T2): G1/4
Probe length including mounthing thread (L2): 250mm
DX - special request - probe diameter = 10mm


Sensors are packed individually into padded cartons.

The packaging includes all information required for proper use and servicing of the equipment.


Physical installation of the sensor

The sensor is screwed onto the measurement place with appropriate spanner (24mm). The threads on the measurement place and sensor must match! Tightness of the connection is ensured by appropriate gasket – not a part of the standard delivery.

The following tables show functionalities of the pins on the sensor side of the connection for different combinations of physical connectors and transciever types.

S1Q connector "A5" with TTL "R0"

Spring pin on sensor Sensor function Notes
7 UART RX 3v3 domain
12 UART TX 3v3 domain
18 DC to power sensor Supply DC power to this pin
19 GND Supply GND to this pin

Other pins must stay unconnected.

Weipu SP2112/P7 "A0" with TTL "R0"

Pin Function Notes
1 not connected leave unconnected
2 GND Supply GND to this pin
3 UART TX 3v3 domain
4 internally shorted to pin 6 leave unconnected
5 VCC Supply DC power to this pin
6 internally shorted to pin 4 leave unconnected
7 UART RX 3v3 domain

Valve connector "A1" with TTL "R0"

Pin number Function Notes
1 VCC Power Supply (+)
2 GND Supply GND (-)to this pin

Valve connector "A1" with RS485 "R1"

Pin number Function Notes
1 VCC Power Supply (+)
2 GND Supply GND (-) to this pin
3 RS485: A
4 RS485: B

Hirschmann CA3GS "A3" with TTL "R0"

Pin number Function Notes
1 VCC Supply DC to this pin
4 GND Supply GND to this pin

Hirschmann CA3GS "A3" with RS485 "R1"

Pin number Function Notes
1 VCC supply DC to this pin
2 RS485: A
3 RS485: B
4 GND Supply GND to this pin

Hirschmann CA6GS "A6" with RS485 "R1"

Hirschmann CA6GS (7pin) connector, for cable connection use Hirschmann CA6LS.

Pin number Function Notes
1 VCC Power supply to sensor - keep powered for autonomous measurements and archiving
3 RS485: A
4 RS485: B
5 keep not connected
6 WAKEUP Pulling low (to GND) wakes up the sensor for communication. Permanently wire to GND to disable sleep.
7 keep not connected

Default connectivity configuration

Default TTL/UART configuration: 38400 baud, 8N1 ( => 1 start bit, 8 data bits, 1 stop bit, no parity)

Default communication protocol: MODBUS - implementation information: ML MODBUS version 1


For support please contact your distributor or manufacturer directly via