I was always taught to count the number of beats over a one minute period.... or you could simply count them over 30 seconds and double the answer. I can understand needing a meter for blood pressure, blood sugar levels etc but not for pulse. However, my bp meter (expensive, just like the one my GP has) also gives me my pulse rate.
To count the beats yourself, get yourself sitting comfortably, then place your index and middle finger of one hand over the wrist of your other hand. When you can feel a distinct beat in your wrist, you can start. You will need a clock or watch with a second hand. As soon as the second hand passes the 12 noon position, start counting the number of beats in your wrist you can feel until the second hand has gone all the way around the clock/watch and a minute has elapsed. The number of beats you have counted is your pulse rate.