SLE 2000 HFO, Service Manual, Page: 213 / 258

Issue 10 (01/10/2004) Page 213 of 258
19.1.4 SI 990301 Calibration of Issue 2 of the A0745 Pressure Drift Board
Introduction
Issue 2 of the Pressure Drift Board (both A0745/01 and A0745/02 ) incorporates an extra
adjustment (RV3) and has a different calibration procedure to issue 1 which only has 2 adjust-
ments. The extra adjustment was introduced because in a small number of cases it was found
that the gain of the pressure transducers varied between samples to such an extent that trans-
ducers could not be matched by offset adjustment alone (over the complete range of the trans-
ducer).
Calibration procedure for the SLE2000HFO.
A0745 board issue 2 (recognisable as having three potentiometers)
a) Whilst monitoring the DC voltage at DIFF, vary the pressure to the proximal airway port
over the complete range (60 to -60cmH2O).
Adjust RV3 until the voltage measured at DIFF is the same at +60cmH
2
O as it is at -60cmH
2
O
to within 20mV. (DIFF should be in the region of 8V).
Pay special attention to the indicated polarities when measuring voltages.
b)
Set the DC voltage between HIGH(+) and LOW(-) to +180mV ±5mV using RV2 .
c) Set the DC voltage between HIGH(+) and DIFF(-) to +90mV ±5mV using RV1 .
d) Repeat steps b) and c) until both voltages are correct to within ±5mV.
Verify that the voltage between DIFF(+) and LOW(-) is +90mV±5mV.
Calibration procedure for the SLE2000HFO ‘PLUS’.
A0745 board issue 2 (recognisable as having three potentiometers)
a) Whilst monitoring the DC voltage at DIFF, vary the pressure to the proximal airway port
over the complete range (140 to -70cmH2O).
Adjust RV3 until the voltage measured at DIFF is the same at +140cmH
2
O as it is at -
70cmH
2
O to within 20mV. (DIFF should be in the region of 8V).
Subject :Calibration of Issue 2 of the A0745 Pressure Drift Board
Equipment :SLE2000 HFO and SLE2000 HFO ‘PLUS’ Infant Ventilators
Serial Numbers :Boards A0745 issue 2 (recognisable as having 3
potentiometers instead of 2)
Service Information Number :Si 990301
Change Note Ref :CN 0625
Date :02/03/99