Vaisala HPP272 - User Manual

Questions and Answers

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Aaron MeyerAug 21, 2025
Why does the measurement reading appear incorrect on my Vaisala HPP272?
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  brittany61Aug 21, 2025
  Incorrect measurement readings in Vaisala Measuring Instruments can stem from several causes. Ensure the temperature probe isn't near a heat source or too close to the H2O2 and humidity probe; relocate it if necessary. If the filter is wet, remove it, drain any water, and allow it to dry, or use nitrogen gas or dry pressurized air to dry it before reinstalling, and perform a chemical purge. A blocked or dirty filter can also cause issues, so replace the filter. Note that if condensation has formed on the sensor when the probe was powered off, it can damage the PEROXCAP sensor, and it cannot be repaired.
M
Michael MckeeAug 23, 2025
What to do if Vaisala Measuring Instruments probe does not power on?
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  Alex MendozaAug 23, 2025
  If your Vaisala Measuring Instruments probe isn't powering on or communicating, first ensure the power input to the probe is on. Check and correct the probe wiring if it's incorrect. Verify that the probe cable is properly connected. Confirm that the operating voltage is correct. If in digital mode, check the communication settings, such as the device address, using the Insight software.
D
Dr. Carol Taylor MDAug 26, 2025
What causes incorrect measurement readings in Vaisala HPP272?
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  Bonnie RogersAug 26, 2025
  If the measurement reading appears incorrect on your Vaisala Measuring Instruments, make sure the filter is installed on the probe and that the yellow transport cap has been removed. If the filter is broken, do not use the probe; remove it and check the sensors. If the sensors are bent, broken, or disconnected, contact Vaisala technical support. If they're intact, change the filter. In analog mode, ensure the maximum load hasn't been exceeded and check the ambient pressure.
M
Matthew YangAug 28, 2025
Why is there no output signal in analog mode on Vaisala HPP272?
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  spencerkristinAug 28, 2025
  If there's no output signal in analog mode (0 mA) for Vaisala Measuring Instruments, check pin #5 to ensure it wasn't floating at start-up or reset, which would indicate the probe is in digital mode. Also, verify that the analog outputs are configured to be on using the Insight software or Modbus configuration registers 0700hex and 0800hex.
V
Vanessa DennisAug 30, 2025
Why is the signal level 0 mA in analog mode for Vaisala Measuring Instruments?
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  Brian FernandezAug 30, 2025
  If you are experiencing no output signal (0 mA) in analog mode with your Vaisala Measuring Instruments, verify that the probe cable is properly connected and that the power input to the probe is on. If the analog output error level is configured to be 0 mA and the probe is performing a start-up purge or is in an error state, wait for 5 minutes for the start-up purge to finish. If the output remains 0 mA after 5 minutes, check the probe diagnostics with the Insight software.
E
Elizabeth ClarkSep 1, 2025
What should I do if the filter is broken on Vaisala HPP272 Measuring Instruments?
- L
  Lucas DavisSep 1, 2025
  If the filter on your Vaisala Measuring Instruments is broken because the probe has fallen or an object has hit the filter, do not use the probe. Remove the filter and visually inspect the sensors. If the sensors are bent, broken, or disconnected, contact Vaisala technical support. If the sensors are intact, replace the filter.
L
Linda JamesSep 4, 2025
Why does Vaisala HPP272 remain in error state in analog mode at start-up?
- K
  Karl TaylorSep 4, 2025
  If the Vaisala Measuring Instruments probe remains in the error state for over 5 minutes at start-up in analog mode, check the analog output scaling with the Insight software and correct it if needed. Also, check the probe diagnostics with the Insight software for any probe or sensor errors.
A
Ann LawrenceSep 6, 2025
How to dry a wet filter on Vaisala HPP272?
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  Andrea LoganSep 6, 2025
  If the filter on your Vaisala Measuring Instruments is wet due to sprayed water entering it during cleaning, remove the filter, pour out any water, and let it dry. Depending on air humidity and temperature, drying in ambient air can take from a few hours to a day. Alternatively, you can dry the removed filter with nitrogen gas or dry pressurized air. Once dry, reinstall the filter and perform a chemical purge.
B
breanna87Sep 8, 2025
What to do with broken filter on Vaisala HPP272?
- J
  Joshua WaltonSep 8, 2025
  If the filter is broken on Vaisala Measuring Instruments, do not use the probe. Remove the filter and visually check the sensors. If the sensors are bent, broken, or disconnected, contact Vaisala technical support. If the sensors are intact, change the filter.
C
Carrie RiversSep 12, 2025
Why does Vaisala HPP272 show H2O2 concentration when not exposed?
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  Amy LeonSep 12, 2025
  If the H2O2 concentration reading on your Vaisala Measuring Instruments shows > 0 ppm even when the probe is not exposed to H2O2, this can be due to normal variation between the two humidity sensors, so no action is required. However, if the reading remains > 0 ppm for 2 to 10 hours, the H2O2 concentration has drifted. To correct this, keep the probe powered on for a few hours in a stable temperature and RH, without exposure to H2O2, as the intelligent measurement algorithm can correct errors of less than 30 ppm itself.

Summary

Product Overview

Basic Features and Options

Lists the key features, measurement capabilities, and connectivity options of the probe.

Safety

Outlines crucial safety warnings and precautions for handling and using the probe.

Measured Parameters

Lists all parameters that the HPP272 probe can measure, with units.

Chemical Purge

Connectivity to Vaisala Insight Software

H2 O2 Measurement

Operating Principle of H2 O2 Measurement

Explains the PEROXCAP sensor technology for measuring H2O2 vapor concentration.

Installation

Wiring

Details the probe's M12/5 pinout, wire colors, and connection requirements.

Power Supply

Specifies the operating voltage range and maximum current consumption for the probe.

Setting Probe in Analog or Digital Mode

Instructions on how to select the probe's output mode using pin #5.

Operation

Probe Start-Up

Behavior at Exposure to H2 O2

Explains the probe's reaction and requirements when exposed to H2O2 condensation.

Operation in Analog Mode

Triggering Purge in Analog Mode

Vaisala Insight Software

Connecting to Insight Software

Step-by-step guide for connecting the probe to the Vaisala Insight software.

Using Probe with Indigo Transmitters

Attaching Probes

Connecting to Wireless Configuration Interface

Details how to enable and access the probe's wireless configuration interface.

Logging in to Wireless Configuration Interface

Explains user levels and the process for logging into the wireless configuration interface.

Maintenance

Cleaning the Probe

Provides instructions and precautions for cleaning the probe body and cable.

Calibration and Adjustment

Troubleshooting

Problems and Their Possible Solutions

Guides users through common operational issues and their potential resolutions.

Analog Output Error State

Describes the conditions that cause the analog output to enter a defined error state.

Technical Data

Measurement Performance

Inputs and Outputs

Appendix A: Modbus Reference

Default Communication Settings

Measurement Data Registers

Lists Modbus registers for reading measurement data values.

Configuration Registers

Lists Modbus registers used for configuring the probe's settings.

Status Registers

Modbus Communication Examples

Provides examples of Modbus requests and responses for reading and writing data.

Technical Support

Vaisala HPP272 Specifications

General

Measurement Parameters	Humidity, Temperature, Pressure
Humidity Measurement Range	0 ... 100 %RH
Protection Class	IP65
Temperature Measurement Range	-40 to +60 °C
Output	RS-485
Power Supply	10...30 VDC
Operating Temperature Range	-40 to +60 °C
Humidity Sensor	Vaisala HUMICAP®