Vaisala HMP45D Manual

USER'S GUIDE

Vaisala HUMICAP® Humidity and

Temperature Probes

HMP45A/D

U274EN-1.2

PUBLISHED BY
Vaisala Oyj	Phone (int.):	+358	9 8949 1
P.O. Box 26	Fax:	+358	9 8949 2227
FIN-00421 Helsinki
Finland

Visit our Internet pages at http://www.vaisala.com/

© Vaisala 2006

No part of this manual may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without prior written permission of the copyright holder.

The contents are subject to change without prior notice.

Please observe that this manual does not create any legally binding obligations for Vaisala towards the customer or end user. All legally binding commitments and agreements are included exclusively in the applicable supply contract or Conditions of Sale.

	HMP45A and HMP45D
U274en-1.2	Operating Manual

1.GENERAL

The HMP45A and HMP45D probes are designed for the measurement of relative humidity and temperature. Humidity measurement is based on the capacitive thin film polymer sensor HUMICAP 180. Temperature measurement is based on resistive platinum sensors (Pt 100 and Pt 1000). Both the humidity and temperature sensors are located at the tip of the probe and in standard version protected by a membrane filter. The HMP45A and HMP45D have a similar humidity output, but the temperature output is active in HMP45A (voltage output 0-1V) and passive in HMP45D (resistive output Pt 100).

2.CONNECTIONS

The cable wires are connected as shown in Figure 1.

Y E L O U T P U T

0...1V=-40...+60 ˚C

B LU V + 7...35VDC

B R N O U T PU T

0...1V=0...100%RH

H M P 4 5 A	V I O G N D

RE D GN D (S E NSE )

GR E Y ( SHIE LD )

	YEL	Pt100
	WHT	Pt100	Pt100
	GRN	Pt100
	BLK	Pt100

	HMP45D	BLU 7...35VDC
		BRN OUTPUT 0...1V=0...100%RH
		VIO GND
		RED GND (SENSE)
		GREY (SHIELD)
		Figure 1 Wire colours

SIGNAL GROUND is used for output signal in a differential measurement. With SIGNAL GROUND, the cable can be extended up to 100 metres without disturbing the measurement accuracy. When outputs are not measured against

SIGNAL GROUND, connect GROUND and SIGNAL GROUND to the same point.

1