Delta PG-40 Specifications download pdf (Page 45)

DELTA LTL-X Retrometer 45

Light trap

The zero signal is simulated by a light trap mounted in the calibration unit in the opposite end

of the reference. It is made of two glossy and black plastic sheets mounted at an acute angle.

If clean this will provide very efficient light absorbing device.

It is necessary to disassemble the light trap to clean it efficiently. Using a fine brush, clean

pressurized air or a soft paper tissue/cloth and some window cleaning liquid can do the clean-

ing.

Calibration

The LTL-X is factory calibrated and very stable but a calibration should always be carried out

before starting a new series of measurements.

The instrument is supplied with two calibration units, a reference calibration unit (black) and

a field calibration unit (red). The reference calibration unit is factory calibrated and traceable

to PTB. The field calibration unit must be calibrated against the reference calibration unit by

the user at suitable intervals. The reference calibration unit is stored in the black protection

box, and the field calibration unit in the gray protection box.

Calibration

Two steps are required for a complete calibration, zero calibration and reference calibra-

tion. The instrument will guide you through the procedure.

Calibration procedure

 Zero calibration

Press the CALIBRATION button once. Mount the instrument upon the calibration

unit. This is done by tilting the instrument slightly backward and then insert the unit

underneath the front end of the instrument. Make sure that the pins on the side of the

unit fit into the slots in the LTL-X.

It is important that the calibration unit faces with the dark opening towards the in-

strument tower. The display will show the correct orientation of the calibration unit.

Make sure that the calibration unit and the light trap are clean.

Press the OK button to start zero calibration. During calibration the lamp will flash a

number of times.

Figure: 6 – Calibration

1 2 ... 40 41 42 43 44 45 46 47 48 49 50 ... 55 56

No comments

Delta PG-40 Specifications Page 45