Display - Michell Instruments Pura User Manual

Pura Online Hygrometer User's Manual
2.1

Display

The instrument has a 4-digit display, set-up on delivery to display a dew-point temperature range of -40ºCdp
(-40ºFdp) (corresponding to a transmitter input of 20 mA), to -120ºCdp (-184ºFdp) (corresponding to a
transmitter input of 4 mA ). Negative temperature readings are signed.
Temperature units are displayed by one of the two LED's located to the left of the display. On delivery, ºCdp
is set-up. If required, the units can be changed to ºFdp. The method of confi guring the unit for ºFdp is
described in Section 3.7.
If the sensor is scaled to output ppm then the instrument can be set-up to read dew point in parts per
V
million (ppm ). This option requires the transmitter to be set-up for ppm either at the time of ordering, or
V V
subsequently via Michell application software. Note: No specifi c ppm LED indicator is provided on the
V
Process Indicator; ppm is selected if neither the ºCdp nor the ºFdp temperature indicators are
V
illuminated.
Two temperature alarm indications are provided by two LEDs located on the right hand side of the display, AL1
(low) and AL2 (high). Access to the alarm relay contacts is provided on the rear panel. The connection for
these alarm relay contacts is shown in Section 3.4.
The operating temperature at which these alarm outputs operate is set-up as shown in Section 3.6.2.
97303 Issue 1.2, March 2016 2 Michell Instruments