Essentials digital EC meter. Convenient and easy to use meter specially designed for testing nutrient solutions. Just immerse the meter's sensor into the nutrient solution and take the reading directly. The meter gives direct accurate readings of nutrient solution and is very helpful in mixing nutrient concentrate with water. All readings are automatically temperature compensated. The meter is easy to use - just dip the sensor into the test solution, stir and wait. The meter will give you a stable reading in about 20 seconds. They have a lifespan of about 1 to 3 years depending on the rate of sampling. All Essential testers are water resistant, which allows for easy washing. Even if the tester is accidently dropped into the water, it will remain afloat so as to enable immediate retrieval without damaging the electronics. The meters are so rugged that they can withstand falls and drop shocks. The meter also has an energy saving feature which shuts off the tester when it is not in use. To ensure accurate reading at all times, the unit displays a low battery symbol to alert the user to change batteries before it degrades the accuracy of important readings.