Vernier RH-BTA Manual

Relative Humidity
Sensor
(Order Code RH-BTA)
The Relative Humidity Sensor can be used to
measure relative humidity in the air as part of a
weather station, or to do any of the following:
Monitor indoor humidity
l
Optimize conditions in a greenhouse or terrarium
l
Determine when static electrical discharges will be a problem
l
Study transpiration rates of plants by monitoring relative humidity in sealed
l
jars containing plants
Note: Vernier products are designed for educational use. Our products are not
designed nor are they recommended for any industrial, medical, or commercial
process such as life support, patient diagnosis, control of a manufacturing
process, or industrial testing of any kind.

Compatible Software

See
www.vernier.com/manuals/rh-bta
Relative Humidity Sensor.

Getting Started

1. Connect the sensor to the interface (LabQuest Mini, LabQuest 2, etc.).
2. Start the appropriate data-collection software (Logger Pro, Logger Lite,
LabQuest App) if not already running, and choose New from File menu. The
software will identify the sensor and load a default data-collection setup.
You are now ready to collect data.
If you are collecting data using a Chromebook™, mobile device such as iPad
or Android™ tablet, or a Vernier wireless sensor or interface, please see the
following link for up-to-date connection information:
www.vernier.com/start/rh-bta

Using the Product

Connect the sensor following the steps in the Getting Started section of this user
manual.

Calibration

Optional Calibration Procedure
You should not have to perform a new calibration when using the Relative
Humidity Sensor. A calibration equation is stored on each Relative Humdity
Sensor before they are shipped, which is used as default by Vernier software. If
you would like to calibrate the Relative Humidity Sensor, you can find
instructions at
www.vernier.com/til/4337
for a list of software compatible with the

Specifications

Range
Power
Response Time
(time for a 90% change in reading)
Resolution:
Stored calibration
Accuracy as shipped
Operating Temperature Range

Care and Maintenance

Do not wrap the cable tightly around the sensor for storage. Repeatedly doing
so can irreparably damage the wires and is not covered under warranty.
The Relative Humidity Sensor should not be used in a condensing environment.
Condensation can damage the probe and is not covered under warranty.

How the Sensor Works

This sensor uses a capacitive polymer to sense humidity. An integrated circuit
then produces an output voltage which varies with relative humidity. The
response time of the unit in moving air is much shorter than in still air. In some
cases, you may want to create air currents (by moving the sensor or using a fan)
to speed up the response of the sensor.
®
The sensor is slightly light sensitive. The housing is designed to minimize the
amount of light that can penetrate the sensor opening. The sensor output is
somewhat affected by temperature. This effect is negligible at low relative
humidity readings, but increases at high humidities. If you want to correct for
this error, you can create different calibration files for different temperatures. In
most cases, this is unnecessary.

Troubleshooting

For troubleshooting and FAQs, see

Repair Information

If you have watched the related product video(s), followed the troubleshooting
steps, and are still having trouble with your Relative Humidity Sensor, contact
Vernier Technical Support at support@vernier.com or call 888-837-6437.
Support specialists will work with you to determine if the unit needs to be sent
in for repair. At that time, a Return Merchandise Authorization (RMA) number
1
0% to 95%
200 μA @ 5 VDC
In still air: 60 minutes
(typical)
With vigorous air movement:
40 seconds (typical)
0.04% RH
slope: 30.43%/V
intercept: –25.81%
±10% RH
0 to 85°C
www.vernier.com/til/1408