Vaisala HPP272, User Manual, Page: 44 / 66

Property Description/Value
Factory calibration uncertainty, at +25 °C (77 °F), 0 ppm H
2
O
2
:
1)
at 0 … 40 %RH ±0.6 %RH
at 40 … 95 %RH ±1 %RH
Temperature
Sensor Pt-1000 RTD Class F0.1
Accuracy over temperature range ±0.2 °C (±0.36 °F)
Other Parameters
Absolute H
2
O
2
, absolute H
2
O, H
2
O ppm by volume, saturation vapor pressure
1) Defined as ±2 standard deviation limits. See also calibration certificate.
Table 6 Inputs and Outputs
Property Description/Value
Operating voltage With digital output: 15 ... 30 VDC
With analog output: 15 ... 25 VDC (use lowest available
operating voltage to minimize heating)
Current Consumption at +25 °C (+77 °F)
In digital mode Max. 15 mA
In analog mode Max. 50 mA
During purge Max. 200 mA
Digital Output
Interface RS-485, not isolated, no line termination
Bit rate 9600, 19200 (default), 38400, 57600, or 115200 bps
Parity None (default), even, odd
Data bits 8
Stop bits 1, 2 (default)
Communication protocol Modbus RTU v.1.02
Analog Output
Outputs 2 × 4 ... 20 mA 3-wire current outputs
Max. load 500 Ω
HPP272 User Guide M211972EN-B
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