Wait another 60 seconds and then compare the colors to those on the side of the can. If a meter is being used, place the strip in the slot at 100-110 seconds. This allows drying time before inserting the strip into the meter. In contrast to the directions on the can, we suggest using only the green block at the top of the strip if this block turns color. We do not recommend trying to average the results of the two blocks.
Some meters also have a way to do a later reading.
Values can be estimated when colors of the strip are between those of the blocks on the can. The Chemstrip bG strips hold their color for two hours after the test, so others can check to see if they agree with the reading. The strips can also be dated and put back in the can if it is desired to keep them longer than two hours. Reasons for a meter not giving a reading are outlined in Table 3 in this chapter. Remember to always record the results of the test in your book and to bring your record book with you to clinic visits.