How to use

The portable and easy to use Greentest device is an express 3-in-1 nitrate, water hardness and background radiation detector. By simply pressing the START button, you can determine in just 3 seconds the amount of nitrates in the food you eat and total dissolved solids (TDS) in the water you drink. Within 10 seconds you can also determine the background radiation levels of your immediate environment and particular objects. For better accuracy while conducting a nitrates test, we recommend you take into account the following measuring tips:

Testing tropical fruit, pomes and other fruits
Including: Pineapple, Jack Fruit, Citrus fruits, Kiwi, Pitaya, Banana, Star fruit (Carambola), Longan, Peach, Mangosteen, Mango, Apple, Pear, Strawberry, Grape.

All fruits in this category can be tested on any side by submerging the probe completely into the skin of the fruit. For very small fruit such as strawberries and grapes, only the first insertion can provide an accurate result. Due to cell destruction after the first measurement, subsequent measurements will provide an innacurate result.
Fruits with big stone(s) or seed(s) should be tested very carefully so the pin of the probe does not touch or comes close to the seed.

Testing gourds, squashes and melons

Including: Bitter gourd, Bell pepper, Pumpkin, Winter melon, Luffa, Eggplant, Marrow, Cucumber, Tomato, Corn, Melon, Watermelon, Honeydew melon, Cantaloupe


These types of fruit and vegetables are better tested from any side but only through the skin. As most are soft inside, the skin will help to keep the device stable during measurement, even slight movements of the device during the testing procedure can distort the final result.

For more accurate results, choose a central location on the side of the fruit or vegetable to test, as this will give you the average nitrate content level of the whole fruit or vegetable.

Don’t forget to remove the bottom and top part of the fruit or vegetable, as the concentration level of nitrates in these parts is higher.

Testing root and tuberous vegetables

Including: Cherry Radish, Turnip, Potato, Purple Potato, Sweet Potato, Taro, Yam Rhizome, Ginger, Carrot.

These types of vegetables can be tested from any side, but we suggest you insert the probe into the core of the stem. Root and bulb vegetables are crispy and brittle, if the probe is inserted laterally, a crack might occur around the pin of the probe creating a space around it. Carefully insert the probe and ensure that it is inserted tightly.

Testing leafy vegetables, bulb and stem vegetables

Including: Asparagus Lettuce, Green Lettuce, Cabbage, Chinese cabbage, Shanghai Green Vegetable, Choy Sum, Pak Choi, Gai-Lan, Cauliflower, Broccoli, Asparagus, Celery, Lotus root, Garlic, Onion, Scallion.

While testing these types of vegetables, please insert the device probe into the center of the head (stem core) of the vegetable ensuring the pin of the probe is NOT between layers or out of the flesh. Remember that any subsequent insertion. up to two cm from the first might display an incorrect result, as after first insertion the cell membranes might be destroyed, vegetable juice will flow out into the intercellular space and this will influence the electrical conductivity performance and final result. Also there is a high risk of getting probe pin into the space of the previous hole.

Due to the structure of these types of vegetables, the core of the stem is the only part that will return a correct result, though they will indicate the highest nitrate level in the tested vegetable.

Step by step guide
  • remove the green cap
  • first clean the probe with a wet and then with a dry tissue
  • switch on the device
  • every time you switch on the device, a calibration is performed, so ensure that the probe is clean and it is not inserted into the testing product
  • refer to settings for “units of weight” and convenient usage
  • choose the product you are going to test from the device list
  • now you can insert the probe into the product, the insertion depth should be full or above 10mm, the tip of the probe should be inserted into the solid mass (flesh) the tip should not come out of the plant, or be inserted into seeds, pits, or inner cavities
  • press the “Start Test” button and hold the device steady during measurement
  • wait 3 seconds and get the result

Refer to below instruction on how to conduct accurate testing without any mistakes for every type of product.