Missing “Vol.” and “No.” in biblatex/biber

Question

I'd like to cite an article with biblatex, but I'm failing to add "Vol." and "No." in front of the corresponding number.

Here is the entry, of type @article, in the .bib file:

@article{kakimoto_monitoring_2006,
    title = {Monitoring of Interarea Oscillation Mode by Synchronized Phasor Mesurement},
    volume = {21},
    issn = {0885-8950},
    doi = {10.1109/TPWRS.2005.861960},
    number = {1},
    journal = {{IEEE} Transactions on Power Systems},
    author = {Kakimoto, Naoto and Sugumi, Masahiro and Makino, Tohru and Tomiyama, Katsuyuki},
    month = feb,
    year = {2006},
    pages = {260 -- 268}
}

I cite it in this minimal example:

\documentclass{scrartcl} 
\usepackage[T1]{fontenc}
\usepackage{selinput}
\SelectInputMappings{
    adieresis={ä},
    germandbls={ß},
    Euro={€},
}

\usepackage[ngerman]{babel}
% erweiterete Literaturverwaltung
\usepackage[  backend = biber   % (bibtex, biber)
        , bibwarn = true    % Warnung bei fehlerhafter bib-Datei
        , style = authoryear
        , natbib = true
          ]{biblatex}
% Einstellung der Anführungszeichen bei Zitaten („x“, »x«, “x”)
\usepackage[autostyle = true]{csquotes}

% Lokalisierung für biber ergänzen % wirkt nicht
\DefineBibliographyStrings{ngerman}{%
      jourvol = {V1ol. }
    , volume = {VolB. }
    , volumes = {VolBs. }
    , edition = {No. }
    %, andothers = {and others}
}
% Trenner zwischen den Namen ein Semikolon
\renewcommand*{\multinamedelim}{\addsemicolon\space}

% Literaturliste laden
\addbibresource{L:/Uni/Literatur.bib} 

\begin{document}

\cite{kakimoto_monitoring_2006}

\printbibliography

\end{document}

But I get in my bibliography this entry:

Kakimoto, Naoto u.a. (Feb. 2006). „Monitoring of Interarea Oscillation Mode by Syn-
chronized Phasor Mesurement“. In: IEEE Transactions on Power Systems 21.1, S. 260–
268. issn: 0885-8950. doi: 10.1109/TPWRS.2005.861960.

As you can see, instead of "Vol. 21, No. 1" I get "21.1".

In my code I tried to change this behaviour with the \DefineBibliographyStrings macro, but without success. It is interesting, that the commented andother localisation string works, the others don't.

Answer 1

As far as I can see, this is not a localization issue, so \DefineBibliographyStrings cannot do anything for you here. You have to modify the field formats. Try:

\DeclareFieldFormat[article]{volume}{Vol. #1}
\DeclareFieldFormat[article]{number}{No. #1}

You can suppress the optional [article] argument if you want this to hold whatever the entry type.