21
Chapter 2
Setting Up
Probe Calibration
Th
e Blood FlowMeter is designed to be easily confi gured and calibrated
for new probes. Th
is operation requires a MLA191 Calibration Kit, which
includes a controlled concentration of latex spheres in suspension. It is
important to follow the instructions provided with the Calibration Kit as
calibration of probes is not possible without it and should not be attempted.
Before starting this it is advisable to have a stable workbench free from
vibration. A clamp to hold the probe reliably in the suspension is provided
in the calibration kit. Set up the probe in the center of the suspension, with
the measuring surface of the probe at a maximum distance from all edges
of the vessel. Follow the procedure below to calibrate the probe. Note that
calibration can be abandoned at any time by removing the probe or by
pressing the CAL button during the calibration.
1. Ensure the probe has been properly initialized for at least 10 minutes
prior to attempting the calibration (see Connecting the Laser Doppler
Probe, p. 18).
2. Using the positioning clamps provided with the MLA191 Calibration
Kit, immerse the probe to mid-depth in the calibration solution.
3. Press the CAL button once. A single beep is emitted, followed by a
series of double beeps, lasting approximately 20 seconds.
4. While the beeping continues, press the CAL button once. A long beep
will sound and the red and amber lights will fl ash for approximately
25 seconds.
5. A double beep will sound to indicate the end of the calibration,
confi rming the calibration. Aft er fi ve seconds, the red indicator light
returns to amber and the unit is ready for use.
During calibration keep the bench free of vibration and movement as this
may invalidate the result. Generally a probe does not require recalibration
unless a new or replacement probe is introduced.
