Having a blood pressure machine is essential when it comes to preventive care. The ability to regularly monitor and measure your blood pressure provides critical information into your condition. Based on the readings, a diagnosis can be made which can help in the management of blood pressure and prevent any future complications. However, all of this is dependent on the accuracy of the reading on which the diagnosis is being made. When it comes to precisely measuring blood pressure, home BP monitors are a must-have.  However, over time, wear and tear can cause inconsistencies and errors to pop up in the reading. In such cases, it is normal to think that your blood pressure machine has become old and faulty. Most people at this time tend to throw away their device and look for a new one. However, such irregularities can be corrected by calibrating your BP monitor and restoring its accuracy to when it was brand new.[1] 

Calibration is important for blood pressure machines to ensure accurate and consistent readings. Over time, a blood pressure machine can become less accurate due to wear and tear. Other factors such as exposure to extreme temperatures or mishandling can also cause the reading to be incorrect over time.[2] 

Here are some precautions you may take to ensure the accuracy of your blood pressure machine: 

1. Check the user manual: All blood pressure machines come with a user manual. The user manual of your blood pressure machine should have instructions on how to calibrate the machine. Follow the instructions to ensure that you calibrate the machine correctly. Some brands like Omron have a dedicated service where experts from the company come and calibrate your device for you. This out-of-house calibration takes 5 to 7 days, so keep that in mind when having your Omron BP monitor calibrated.  
2. Use a certified calibration device: To ensure that your blood pressure machine is giving accurate readings, you need to use a certified calibration device. You can purchase one online or from a medical supply store. If you are having your blood pressure machine calibrated by a third-party, make sure to ask them to use a certified calibration device as well. This will help ensure that your blood pressure readings are accurate and reliable.[3]     
3. Follow a regular calibration schedule: Calibration should be performed on a regular schedule to ensure accuracy. The frequency of calibration depends on the type and usage of the machine. Typically, a blood pressure machine is calibrated once every 2 to 3 years. However, it is recommended to calibrate a blood pressure machine at least once a year. 
4. Store the machine properly: Storing your blood pressure monitor properly can significantly extend its life.  Blood pressure machines should be stored in a safe and secure place that is free from extreme temperatures, moisture, and shock. When purchasing your BP machine, the user manual that comes with contains instructions on how to properly maintain and store your device.  
5. Check for accuracy: After calibrating the machine, test it against a known standard to verify its accuracy. You can do this by comparing the readings from your machine to those taken by a healthcare professional or another calibrated blood pressure machine. You can either have your device tested on someone you know to have normal blood pressure, or you can have the readings compared with the ones taken by a doctor in a clinical setting. If the readings are the same, then you can be sure that your blood pressure monitor is accurate. If the readings differ, then you may need to have it re-calibrated or check for any defects. 
6. By following these steps, you can ensure that your blood pressure machine is accurate and reliable. Accurate blood pressure readings are crucial for effective management of high blood pressure and other related health conditions. Making sure that you have an accurate and reliable device is essential to be able to track any changes and irregularities in your blood pressure. Having your BP monitor calibrated allows you the opportunity to increase the longevity and usefulness of your device.  

References 

1. Measure Your Blood Pressure | cdc.gov 
2. Calibration, Maintenance, and Use of Blood Pressure Devices – The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure – NCBI Bookshelf (nih.gov) 
3. How to Calibrate a Blood Pressure Monitor | Healthfully