HYGROMETER and/or THERMOMETER LB-712TW

functions: thermometer, hygrometer (humidity meter)
measurement: temperature, air relative humidity
wide scope of work temperatures
outputs: 4/20mA, 0/1V or 0/10V

Description

Hytherograph LB-712TW is designed for air temperature and relative humidity measurement. It can work in places where there is great dustiness, since it has a hermetic casing and an adequate filter, which protects the measurement sensors. It is a stationary device of small size, powered from an outside power supply.

The device consists of two totally electrically independent parts: a thermometer and a hygrometer (humidity meter). The only thing that connects those two parts of the device is a shared construction plate and a casing. Each one of those parts can be made in three versions: with a digital current loop 4..20mA (I), with a voltage output 0..1V (N1) or with a voltage output 0..10V (N10). Additionally a hygrometer can be custom made for standard scope of humidity measurement 10..95% or for an extended scope 0..100% (H). The thermometer can be made with a temperature sensor placed in a casing (standard version) or with a temperature sensor made in a form of an external probe (LB-712TZ), two or four cable (in this case it has to be only a thermometer without a hygrometer). There are also possible other versions of the device: a hygrometer (LB-712W) or a thermometer (LB-712T). The device's output measurement signal is made in a form of screw terminals that are placed inside of the casing to which a cable is attached using a whole of 7 mm in diameter. In the version LB-712Y the device has a SzR14 type connection.

Hytherograph LB-712 can be made in a special "S" version (in a silicone filing compound), equipped with a silicone casing screen type F4, what makes the electronic system resistant to high humidity. Independently from the ("S") type version the device cannot be exposed to direct precipitation and out dropping water vapor. That is why in the open space conditions it is recommended that it should be placed (i.e. in a meteorological cage).

Except from the analogous measurement result output the construction of the main part of the device is digital and based on an efficient and energy saving microprocessor controller. The device's standard version is adapted for short time (up to few hours) measurements on the ends of measurement scopes, except from that the device should stay in the recommended constant work conditions. The device in a standard version is equipped with a sensor shield (pollution filter) type F3.

Hytherograph LB-712TW is calibrated in a climate chamber and the calibration data from the humidity and temperature sensors is stored in a digital nonvolatile memory of the device and is used during measurements for calculating of the final results. The calculations made by the device's microprocessor are made very precisely and take into consideration the nonlinear measurement characteristics of the humidity and temperature sensors.The calculations take under consideration the calibration data from the output voltage
converter or the current loop.

The main features that distinguish the device are as follow:

wide scope of work temperatures (-40°C ..+85°C),
precise, numeric measurement procedure,
possibility of numerous calibrations through a RS-232C interface (lack of regulation elements, i.e. potentiometers),
wide scope of power supply voltage,
power supply line is common with the output current loop line (for version 4-20 mA).

Each hytherograph (upon a request) can have an individual calibration certificate issued by the LAB-EL Calibration Laboratory.

Technical data

TEMPERATURE MEASUREMENT
Measurement inaccuracy	+/- 0.3°C
Scope of measurement	-40..+85°C
Scope of measurement	-100..+200°C	for LB-712TZ, programmed scope, external probe
Measurement resolution	+/- 0,1%	programmable measurement scope

HUMIDITY MEASUREMENT
Measurement inaccuracy	+/- 2.5%	in the scope of 10...90%
Measurement inaccuracy	+/- 4.5%	outside of the scope 10...90%
Scope of measurement LB-712	10..95%	for temperatures up to +40°C
	10..60%	for temperatures up to +70°C
	10..40%	for temperatures up to +85°C
Measurement resolution	+/- 0,2%

ANALOG OUTPUTS
version	output	for 0% RH (or for the beginning of a thermometer range)	for 100% RH (or the end of a thermometer range)	power supply voltage	energy consumption
LB-712	current loop	4 mA	20 mA	10..29V DC	max. 20mA
LB-712N1	voltage	0 V	1 V	10..29V DC	max. 3mA
LB-712N10	voltage	0 V	10 V	17..29V DC	max. 10mA

RECOMMENDED CONSTANT WORK CONDITIONS *)
Scope of temperatures	0..40°C
Scope of humidity	20..80%
Level of environment corrosion aggressiveness accord. PN-71/H-04651	B
Level of casing protection	IP 65 limited additionally by the class of filter protection

*) - Going beyond recommended constant work conditions (i.e. when installing the device in the open space) requires using additional protection means for the device's electronic part so that water out dropping does not start inside of the device (protecting the electronics with silicone or using additional external casing).

CALIBRATION INTERFACE

Standard RS-232C, transmission speed 30 bits/s, 7 information bits, 1 start bit and 1 bit stop.

OVERALL DIMENSIONS

Approximately 170 x 64 x 35 mm (overall dimensions with pulled out protection shield and with a pass).

EXTENDED VERSIONS

LB-712Z with a connection SzR14

LB-712S - with greater resistance to climate conditions (in a silicone filling),
LB-712Fn - sensor protection version (according to a description), the version is given
if it is different than F3,
LB-712Z - with an addition connection SzR14 (instead of the terminals inside of the casing).

DETAILED QUALITY OF WORK DENOTATION

Various versions of the device LB-712TW have the following detailed descriptions:

LB-712 T/aaa/zp/zk/W/bbb/c

The following description fields:

LB-712 - device name,
T- beginning of the field thermometer version,
aaa - thermometer version: I - current loop 4..20mA, N1 - voltage output 0..1V, N10 - voltage output 0..10V,
zp -beginning of the thermometer measurement scope,
zk - end of the thermometer measurement scope,
W - beginning of the hygrometer field version,
bbb - hygrometer version: I - current loop 4..20mA, N1 - voltage output 0..1V, N10 - voltage output 0..10V,
c - optional characters that can appear at the end of a symbol, if the quality of work is different than a standard (standard quality of work: internal sensors, F3 shield, scope of humidity measurement 10..95%, output line clips inside a casing, lack of silicone filing) then those characters can take the following values:

S - special version with a silicone filling,
H - extended scope of humidity measurement from 0 to 100%,
Fn - sensors shield version, version is provided if it is different than F3,
X - external probe for temperature measurement PT1000 (an external probe is only available for LB-712T),
U - external probe for temperature measurement Pt100 (an external probe is only available for LB-712T),
Z - with a terminal connection SzR14 (instead of clips inside a casing) see picture.

Examples:

LB-712 T/I/W/I - both a thermometer and a hygrometer in a current version, thermometer with and an internal sensor, a hygrometer for standard scope of humidity measurement 10 .. 95%.
LB-712 T/I/W/N10/S - a thermometer with a current output and an internal sensor, a hygrometer with a voltage output 0..10V in a silicone filling.
LB-712 W/N1 - only a hygrometer with a standard scope of humidity measurement and a voltage output 0..1V.

If a hytherograph is ordered with an external temperature sensor (symbol X lub U), then along with a version specification a commentary should be provided concerning a probe: number of conductors of cable (2 or 4), probe cable length, probe overall dimensions (length and diameter) or its type.

Example:

LB-712 T/IZ/-10/+20/X, 4 conductors of cable, cable length 10m, probe length 10cm, diameter 6mm - LB-712 specification with: current output, scope of measurement from -10 to +20°C,external probe for temperature measurement and a detailed description of the external probe construction.

GOOD CLIMATE IS FAVORABLE

Produced by: LAB-EL Laboratory Electronics
68b, Bodycha Str., 02-495 Warsaw
tel: (022) 667 71 18, 0601 209656, fax: (022) 867 53 32
e mail: info@label.com.pl
home page: http://www.label.com.pl
internet meteorological station: http://www.meteo.waw.pl
meteorological station on a mobile phone: wap.meteo.waw.pl
Last updated: 20.05.2011