Campbell HMP60 User manual

Revision: 10/2021
Copyright © 1995 – 2021
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Precautions 1
3. Initial inspection 1
4. QuickStart 2
5. Overview 4
6. Specifications 5
6.1 Temperature sensor 5
6.2 Relative humidity sensor 5
7. Installation 6
7.1 Wiring to data logger 6
7.2 Data logger programming 7
7.2.1 VoltSE() instruction 7
7.3 Mounting 8
7.3.1 Installation in a 41303-5A or 41303-5B 6-plate shield 9
7.3.2 Installation in a RAD06 6-plate shield or RAD10 10-plate shield 10
7.3.3 Mount the shield 10
8. Operation 11
8.1 Measurement 11
8.2 Long cable lengths 11
8.3 Absolute humidity 12
9. Troubleshooting and maintenance 13
9.1 Troubleshooting 13
9.2 Maintenance 13
9.2.1 Procedure for removing RH chip 14
10. Attributions and References 15
Appendix A. Importing Short Cut code into CRBasic Editor 16
Appendix B. Example programs 17
Table of contents - i

1. Introduction
The HMP60 probe measures temperature for the range of –40 to 60°C, and relative humidity for
the range of 0 to 100% RH. It is suitable for long-term, unattended monitoring, and is compatible
with all Campbell Scientific data loggers.
For Edlog data logger support, check the availability of an older manual at
www.campbellsci.com/old-manuals .
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lCare should be taken when opening the shipping package to not damage or cut the cable
jacket. If damage to the cable is suspected, contact Campbell Scientific.
lAlthough the HMP60 is rugged, it should be handled as a precision scientific instrument.
lDo not touch the sensor element.
lRemove the yellow cap prior to installation.
lSantoprene® rubber, which composes the black outer jacket of the cable, will support
combustion in air. It is used because of its resistance to temperature extremes, moisture,
and UV degradation. It is rated as slow burning when tested according to U.L. 94 H.B. and
passes FMVSS302. However, local fire codes may preclude its use inside buildings.
3. Initial inspection
lUpon receipt of the HMP60, inspect the packaging and contents for damage. File damage
claims with the shipping company.
lThe model number and cable length are printed on a label at the connection end of the
cable. Check this information against the shipping documents to ensure the expected
product and cable length were received.
HMP60 Temperature and Relative Humidity Probe 1

4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-data logger-getting-started-program-part-3 .Short
Cut is an easy way to program your data logger to measure the sensor and assign data logger
wiring terminals. Short Cut is available as a download on www.campbellsci.com . It is included
in installations of LoggerNet,RTDAQ, and PC400.
Use the following procedure to get started.
1. Open Short Cut and click Create New Program.
2. Double-click the data logger model.
3. In the Available Sensors and Devices box, type HMP60 or locate the sensor in the Sensors >
Meteorological >Relative Humidity & Temperature >HMP50/HMP60 Temperature &
Relativite Humidity folder. Double-click HMP50/HMP60 Temperature & Relative Humidity
Sensor. Data defaults to degree Celsius. This can be changed by clicking the Deg C box and
selecting Deg F, for degrees Fahrenheit, or Kfor Kelvin.
HMP60 Temperature and Relative Humidity Probe 2

4. Click the Wiring tab to see how the sensor is to be wired to the data logger. Click OK after
wiring the sensor.
5. Repeat steps three and four for other sensors.
6. In Output Setup, type the scan rate, meaningful table names, and Data Output Storage
Interval.
HMP60 Temperature and Relative Humidity Probe 3

7. Select the measurement and its associated output option.
8. Click Finish and save the program. Send the program to the data logger if the data logger
is connected to the computer.
9. If the sensor is connected to the data logger, check the output of the sensor in the data
display in LoggerNet,RTDAQ, or PC400 to make sure it is making reasonable
measurements.
5. Overview
The HMP60 Temperature and Relative Humidity probe contains a Platinum Resistance
Temperature detector (PRT) and a Vaisala INTERCAP® capacitive relative humidity sensor. It is
suitable for long-term, unattended monitoring. The humidity chip is field-replaceable,
eliminating recalibration downtime.
Features:
lField-replaceable humidity chip eliminates recalibration down time
lCompatible with the following data loggers: CR6, CR1000X, CR800 series, CR350 series,
CR300 series, CR3000, CR1000
HMP60 Temperature and Relative Humidity Probe 4

6. Specifications
Operating temperature: –40 to 60 °C
Probe length: 7.1 cm (2.8 in)
Probe body diameter: 1.2 cm (0.47 in)
Filter: 0.2 μm Teflon membrane
Filter diameter: 1.2 cm (0.47 in)
Housing
Body material: AISI 316 stainless steel
Filter cap material: Chrome-coated ABS plastic
Classification: IP65
Power consumption: 1 mA typical; 5 mA maximum
Supply voltage: 5 to 28 VDC
Settling time after power is
switched on: 1 s
Output signal range: 0 to 1 VDC
6.1 Temperature sensor
Sensor: 1000 Ω PRT, DIN 43760B
Temperature
measurement range: –40 to 60 °C
Temperature accuracy: ±0.6 °C (–40 to 60 °C)
6.2 Relative humidity sensor
Sensor: INTERCAP®
Relative humidity
measurement range: 0 to 100% non-condensing
HMP60 Temperature and Relative Humidity Probe 5

Typical accuracy
from 0 to 40 °C: ±3% RH over 0 to 90%
±5% RH over 90 to 100%
Typical Accuracy
from –40 to 0 °C
and 40 to 60 °C: ±5% RH over 0 to 90%
±7% RH over 90 to 100%
7. Installation
If you are programming your data logger with Short Cut, skip Wiring to data logger (p. 6) and
Data logger programming (p. 7). Short Cut does this work for you. See QuickStart (p. 2) for a
Short Cut tutorial.
7.1 Wiring to data logger
CAUTION:
Always connect the blue wire to the data logger first, followed by the black, white, and clear
wires. Connect the brown (power) wire last.
Table 7-1: Wire color, function, and data logger connection
Wire color Wire function Data logger connection terminal
Black Temperature signal Uconfigured for single-ended analog input1,
SE (single-ended, analog-voltage input)
White Relative humidity signal Uconfigured for single-ended analog input,
SE
Blue Power ground and
signal reference G
Brown Power 12V or SW12
Clear EMF Shield ⏚(analog ground)
1Uterminals are automatically configured by the measurement instruction.
HMP60 Temperature and Relative Humidity Probe 6

7.2 Data logger programming
Short Cut is the best source for up-to-date programming code for Campbell Scientific data
loggers. If your data acquisition requirements are simple, you can probably create and maintain a
data logger program exclusively with Short Cut. If your data acquisition needs are more complex,
the files that Short Cut creates are a great source for programming code to start a new program
or add to an existing custom program.
NOTE:
Short Cut cannot edit programs after they are imported and edited in CRBasic Editor.
AShort Cut tutorial is available in QuickStart (p. 2). If you wish to import Short Cut code into
CRBasic Editor to create or add to a customized program, follow the procedure in Importing
Short Cut code into CRBasic Editor (p. 16). Programming basics for CRBasic data loggers are
provided in the following sections. Complete program examples for select data loggers can be
found in Example programs (p. 17).
Measure the HMP60 with either the VoltSE() or VoltDiff() measurement instruction as
described in the following sections.
For a discussion on errors caused by long cable lengths, see Long cable lengths (p. 11).
7.2.1 VoltSE() instruction
When cable lengths are shorter than 6.1 meters or when power is switched, use the VoltSE()
measurement instruction to measure the temperature and relative humidity. The HMP60 output
scale is 0 to 1000 millivolts for the temperature range of –40 to 60°C and for the relative humidity
range of 0 to 100%.
VoltSE(Dest, Reps, Range, SEChan, MeasOff, SettlingTime, Integ/FNotch, Mult, Offset)
Variations:
lTemperature reported as °C – set Mult to 0.1 and Offset to –40
lTemperature reported as °F – set Mult to .18 and Offset to –40
lHumidity reported as a percent – set Mult to 0.1 and Offset to 0
lHumidity reported as a fraction – set Mult to 0.001 and Offset to 0
HMP60 Temperature and Relative Humidity Probe 7

NOTE:
When the probe is connected to a CS110 Electric Field Meter, the probe is measured by the
CS110 internal CR1000 data logger module using VoltSE() instructions. Relative humidity
and temperature signals are measured on single-ended terminals 1 and 2, respectively.
250µs integration should be used in the VoltSE() instructions.
7.3 Mounting
Sensors should be located over an open level area at least 9m (EPA) in diameter. The surface
should be covered by short grass or the natural earth surface where grass does not grow.
Sensors should be located at a distance of at least four times the height of any nearby
obstruction, and at least 30m (EPA) from large, paved areas. Sensors should be protected from
thermal radiation, and adequately ventilated.
Standard measurement heights:
1.5 m (AASC)
1.25 to 2.0 m (WMO)
2.0 m (EPA)
See Attributions and References (p. 15) for a list of references that discuss temperature and
relative humidity sensors.
When used in the field, the HMP60 must be housed inside a solar radiation shield. Typically, the
41303-5A or RAD06 6-plate solar radiation shield is used. The HMP60 is held within the 41303-5A
by a mounting clamp (FIGURE 7-2 (p. 9)).
This probe may also be housed in a 41003-5 or RAD10 10-plate shield. Additional hardware must
be used with the 41003-5. No additional hardware is required with the RAD10. A 10-plate shield
adapter allows the HMP60 to be mounted in the lower part of the 41003-5 shield.
The white color of these shields reflects solar radiation, and the louvered construction allows air
to pass freely through, thereby keeping the probe at or near ambient temperature. The RAD06
and RAD10 use a double-louvered design that offers improved sensor protection from insect
intrusion and driving rain and snow. In addition, the RAD06 and RAD10 shields have lower self-
heating in bright sunlight combined with higher temperatures (>24°C (75°F)) and low wind
speeds (<2m/s (4.5mph)), giving a better measurement.
Each of these solar radiation shields attaches to a crossarm, mast, or user-supplied pipe with a 2.5
to 5.3cm (1.0 to 2.1in) outer diameter.
HMP60 Temperature and Relative Humidity Probe 8