Step-by-Step Guide

The BL-5406-KIT pressure sensor can be used to monitor water levels in tanks or cisterns. While these sensors are commonly used to monitor water pressure in irrigation main lines, they are versatile enough to indicate water levels in a body of water and even automate decisions based on those levels.

Required Hardware

You will need the following components to monitor water levels:

• BaseStation 3200
• BL-5406-KIT pressure sensor
• Quarter inch threaded inlet at the bottom of the tank
• Your body of water (tank or cistern)

Installing the Pressure Sensor

1. Mount the pressure sensor portion of the kit as low on the tank as possible. A quarter inch outlet like a tee works well, or you can install your own.

2. Once the sensor is installed, connect the BiCoder to the two wire path.

3. Follow the manufacturer's instructions for connecting the included DBRY-6 splices. Make sure that you get the red and black wire polarity correct.

Configuring the Sensor in BaseManager

1. Open BaseManager and go to Devices.

2. Search the wire path for pressure sensors.

3. Give your new sensor a unique name and then save before leaving.

4. Once the sensor is assigned, you can use the test function to see the water pressure, or you can go to Quick View and see the pressure there as well.

Understanding Pressure-to-Water Level Conversion

The pressure reading corresponds directly to the water level in the tank. Each foot of water provides 0.433 PSI of pressure. This relationship allows you to calculate water levels based on pressure readings.

For example, a tank that is 20 feet tall will show:

• 8.66 PSI when completely full
• 4.33 PSI when half full
• 2.16 PSI when a quarter full

The pressure reading will consistently correspond to the same water level mark every single time the sensor reads that value.

Creating a Water Source Empty Condition

A water source empty condition will discontinue the use of a water source when the sensor indicates that the water source or tank is empty and unusable.

1. Begin at the Flow Setup tab.

2. Go to Water Sources, then select Edit.

3. Click Add Empty Condition to see the different sensor options.

4. Since you named your pressure sensor earlier, it will be easy to find that device.

5. At Empty Condition PSI, set it to less than 0.43 PSI. This pressure corresponds with one foot of water, the lowest level that you're willing to accept in the tank.

6. For Wait Time, set it to 120 minutes (two hours).

7. Check Enabled and then save the program.

Here's what happens with these values: 

When the tank drains down to that lowest level and the sensor reads 0.43 PSI or less, this water source can't be used and it's taken offline. After two hours, it will check to see if the water level has come up again. If the level has increased and there's more than 0.43 PSI at the sensor, the tank water source will resume watering. If the tank is still dry or below that one foot level, it will wait another two hours before checking again.

Water source empty conditions are a great way to ensure that a tank or other water source isn't used when the water level is just too low.

Starting a Tank Fill Program Based on Water Level

You can automate tank filling by starting a program when the water level drops below a certain threshold.

1. Begin at the Schedules tab.

2. Add a new program, then name it.

3. Select the zone that fills the tank (for example, zone 6).

4. Add a runtime for the zone. For example, try 120 minutes. You'll need to do some math to make sure the tank fills up in two hours but doesn't overfill.

5. Make sure that the entire water window is available.

6. Remove the start time and allow only start days. Date and time are the most common conditions to start a program, but not the only ones.

7. For your tank, select Add a Condition from the drop down and use a pressure sensor to start a program.

8. At the device list, make sure that you're using your previously assigned tank level sensor.

9. Set the pressure limit to less than 0.86 PSI so it reflects a two foot lower water limit.

10. Click Save.

The program will start when the water level is low enough for the pressure sensor to read 0.86 PSI or less. The zone will run for two hours, filling the tank back up.

Preventing Tank Overfill with a Pressure-Based Stop Condition

There may be times when you can't calculate the fill time precisely but still want to avoid overfilling the tank. You can set a program stop condition based on pressure to prevent this.

1. Change the runtime so that it's more than long enough to fill the tank, such as four hours.

2. Since a four hour runtime could overfill the tank, you need to stop the program before then. Select Add a Condition and from the drop down, use a pressure sensor to stop a program.

3. At the device list, make sure that you're using the same tank level sensor.

4. Set the pressure limit to 8.3 PSI or above so it reflects the upper limit of your 20 foot tall tank.

5. Be sure to uncheck Finish Run so the program stops prior to that four hour runtime.

6. It's a good idea to have a little time before the overfill happens to allow for the controller response time.

Here's what happens with this program: 

When the tank drains down to that lowest level and the sensor reads 0.43 PSI or less, the program will start filling the tank. The zone can run as long as four hours, but when the pressure sensor reads 8.3 PSI or more, the program will stop before the tank overfills.

Video Walkthrough

Video originally published February 2023.

If you have questions, here are 3 ways to get answers:

1. Search within this Baseline knowledgebase

2. Visit the Baseline support page

3. Call 866-294-5847 or email support@baselinesystems.com, hours are from 6:00 am to 7:00 pm Eastern Time or 4:00 am to 5:00 pm Pacific Time.