HF scientific Micro1000 Laboratory Turbidimeter - 0-10,000 NTU - Manual (Page 26)

Rev. 3.2 20
7. Troubleshooting
7.1. System Warning Message(s)
The instrument generates warning messages to provide you with specific diagnostic information about
the instrument. These messages are for your use and do not reduce the performance of the instrument.
The following sections outline warning messages that could be observed during normal operation.
7.1.1. Flashing “Cal” block
A flashing "Cal" block observed during normal automatic mode indicates that you should re-
calibrate your instrument.
The factory default is 30 days. HF scientific inc. recommends calibration every 30 days. The
flashing "Cal” block is only a warning and does not mean that the instrument will stop performing
accurately. The "Cal" block will flash until you have re-calibrated the instrument.
7.1.2. Sample Over-Range (“O-r”)
The instrument is capable of reading the turbidity of samples up to 10,000 NTU (or equivalent in the
other scales). If the turbidity of the sample is determined to be higher than 10,000 NTU, the
instrument will report “O-r” in the upper row of the display.